Type of Source
Go to ...When you use the words or original ideas of another person in your writing, you need to document, or give credit to, the sources of those words or ideas. If exact words from the original are used, quotation marks are necessary. If you paraphrase or restate the idea in your own words, quotation marks are not required, but documentation of the source is still required.
There are several different formats for documentation. This page explains the CSE (Council of Science Editors) format. In this format, you briefly identify your sources in the text of your paper, then give the full information in the list of references at the end of the paper.
The CSE style manual describes two systems of documentation:
Your instructor can tell you which method or system to use.
According to CSE style, you identify in the text of your paper the sources of information (references) you have used. This serves the same purpose as "footnotes," but is integrated smoothly into the text of your paper, rather than listed separately. The CSE style offers several systems of citing your references. This handout illustrates the Citation-Sequence system.
As each source is mentioned in the text, it is numbered in sequence. Page numbers are not added.
Ozone plays an important role in photochemical smog and in the production of acid rain.1
If a source is used again later, the original number is reused.
"The American Lung Association (ALA) reports that lung disease is now the third leading cause of death in the country and the fastest growing among the top five causes and that ozone pollution contributes to this deadly trend."8
On the other hand, atmospheric ozone absorbs ultraviolet radiation with wavelengths between 240 and 320 nanometers which is lethal to simple unicellular organisms and the surface cells of higher plants and animals.1
The complete references are listed at the end of the paper in the order they were numbered in your paper.
The list of references (or bibliography) at the end of your paper should be a list of all the sources that contributed ideas and information to your paper. It can be titled "References" or "Cited References."
The arrangement of references in your list depends upon how you have cited them in your text. In the Citation-Sequence system, each reference appears in the order that it is first mentioned in your paper.
**If you have a type of source not covered by the example reference list below, ask a librarian to show you the CSE style manual, Scientific Style and Format: The CSE Manual for Authors, Editors, and Publishers, 8th ed. Chicago (IL): University of Chicago Press; 2014. REF T11 .S386 2014.
It is based on Citing Medicine, 2nd edition: The NLM Style Guide for Authors, Editors, and Publishers which is the NLM Style: http://www.ncbi.nlm.nih.gov/books/NBK7256/. CSE's link for citing sources accessed via the Internet is very detailed and based on NLM style, so librarian assistance is recommended in using it: http://www.ncbi.nlm.nih.gov/books/NBK7277/
The AMA citation format provided by some library databases, such as EBSCO's Academic Search Complete, is very similar to CSE.
This option is available when emailing articles 
or from 
in the detailed record's Tools.
Online (web) sources indicated with double plus sign ++
Note: Write down the URL and date accessed for citations when downloading. They may not appear on printouts.
| Reference Type: | List Example: |
|---|---|
| Signed encyclopedia article | 1. Prinn RG. Atmospheric ozone. In: McGraw-Hill encyclopedia of science and technology. 7th ed. Vol. 2. New York: McGraw-Hill; 1992. p. 229-232. |
| ++ Signed encyclopedia article found in an online database (example one) | 9. Brasseur GP, Prinn RG. Stratospheric ozone. In: AccessScience @ McGraw-Hill: encyclopedia of science and technology online [database on the Internet]. 2007-19 ed. [New York]: McGraw-Hill; 2018. [accessed 2019 Mar 13]. https://www.accessscience.com/. |
| ++ Signed encyclopedia article found in an online database (example two) | 11. Young CT and updated by staff. Nuts. In: Kirk-Othmer encyclopedia of chemical technology [database on the Internet]. 1999-2019 ed. Hoboken (NJ): Wiley; 2007. [accessed 2019 Mar 13]. https://onlinelibrary.wiley.com/doi/book/10.1002/0471238961. |
| ++ Signed encyclopedia article found in an online database (example three) | 2. Uretsky S, Davidson T. Antacids. In: Gale encyclopedia of medicine [database on the Internet]. 5th ed. Vol. 1. Farmington Hills (MI): Gale; 2015. [accessed 2019 Mar 13]. (Gale Virtual Reference Library). p. 290-292. https://go.galegroup.com/ps/start.do?p=GVRL. |
| ++ Signed encyclopedia article found in an online database (example four) | 3. Uretsky S, Davidson T, Longe JL. Antacids. In: Gale encyclopedia of medicine [database on the Internet]. 3rd ed. Detroit (MI): Thomson Gale; 2006. [accessed 2009 Oct 22]. (Health Reference Center Academic). [about 2 p.]. https://find.galegroup.com/gtx/start.do?prodId=HRCA. |
| ++ Signed encyclopedia article found in an online database (example five) | 23. Luster M, Simeonova P, Germolec D. Immunotoxicology. In: Encyclopedia of life sciences [database on the Internet]. 1999-2013 ed. Hoboken, NJ: Wiley; 2008. [accessed 2013 Feb 20]. http://onlinelibrary.wiley.com/mrw/advanced/search?doi=10.1002/047001590X. |
| Reference Type: | List Example: |
|---|---|
| Journal article with three authors | 15. Bekki S, Law KS, Pyle JA. Effect of ozone depletion on atmospheric CH(4) and CO concentrations. Nature. 1994 Oct 13;371(6498):595-597. |
| Magazine article with author and discontinuous pages | 7. William P. The ozone below. Audubon. 1994 Sep-Oct;96(5):14, 22-23. |
| Newspaper article with author | 8. Browne MW. Antarctica's ozone layer is threatened by depletion. NY Times. 1994 Oct 8;Sect A:7(col 6). |
| ++ Science magazine article found in an online database | 21. Travis J. Toxin trumped. Science News. 2002 Aug 17:99. In: Academic Search Complete [database on the Internet]. Ipswich (MA): EBSCO [accessed 2019 Mar 19]. https://search.ebscohost.com/. |
| ++ Journal article examples for same article found in two different indexes: | |
| ++ Journal article found in an online database with first page number and then number of pages given and all multiple authors listed | 12. Chiuchiolo AL, Dickhut RM, Cochran MA, Ducklow HW. Persistent organic pollutants at the base of the Antarctic marine food web. Environmental Science & Technology. 2004;38(13):3551-3557. In: Academic Search Complete [database on the Internet]. Ipswich (MA): EBSCO [accessed 2006 Sep 5]. 7 p. http://search.ebscohost.com/. |
| ++ Journal article found in an online database with page number range given and all multiple authors listed | 13. Chiuchiolo AL, Dickhut RM, Cochran MA, Ducklow HW. Persistent organic pollutants at the base of the Antarctic marine food web. Environmental Science & Technology. 2004;38(13):3551-3557. In: American Chemical Society Publications: Journals and Magazines [database on the Internet]. Washington (DC): ACS; c2000-2019 [accessed 2019 Mar 13]. https://pubs.acs.org/about.html. |
| ++ Newspaper article found online | 20. Brody J. Cutting cholesterol, an uphill battle. The New York Times [Internet]. 2007 Aug 21. [accessed 2007 Sep 27]. http://www.nytimes.com/2007/08/21/health/21brod.html?_r=1&oref=slogin. |
| ++ Abstract found in an online database | 6. Rigos G, Nengas I, Alexis M, Troisi GM. Potential drug (oxytetracycline and oxolinic acid) pollution from Mediterranean sparid fish farms [abstract]. Aquatic Toxicology. 2004 Aug 25;69(3):281-8. In: PubMed [database on the Internet]. Washington (DC): NLM [accessed 2019 Mar 13]. https://www.ncbi.nlm.nih.gov/entrez/. |
| Reference Type: | List Example: |
|---|---|
| ++ Electronic Book (e-book) | 22. Neidle S. Principles of nucleic acid structure [electronic resource]. Amsterdam: Elsevier; Boston: Academic Press; 2008. [accessed 2019 Mar 13]. 289 p. https://www.ebscohost.com/ebooks/home. |
| Book with author | 19. Pulford I. Environmental chemistry at a glance. Oxford; Malden (MA): Blackwell Pub.; 2006. 132 p. |
| Book with two authors | 10. Andersen S, Sarma K. Protecting the ozone layer: the United Nations history. London: Earthscan Publications; 2002. 400 p. |
| Book with organization as author | 4. National Research Council. Ozone-forming potential of reformulated gasoline. Washington (DC): National Academy Press; 1999. 212 p. |
| Book with an editor | 5. McCuen GE, editor. Our endangered atmosphere: global warming and the ozone layer. Hudson (WI): Gary E. McCuen Publications; 1987. 133 p. |
| Work within a larger work | 14. Mackenzie D. Anybody want to save the ozone layer? In: Gribbin J, editor. The breathing planet. New York: Basil Blackwell; 1986. p. 185-192. |
| Reference Type: | List Example: |
|---|---|
| Pamphlet with no author, no city or publication, no dates | 18. Can we save the ozone layer? [place unknown]: Concerned Citizen Press; [date unknown]. |
| ++ WWW site | 16. Careers in chemical engineering - what do chemical engineers do? [Internet]. New York (NY): American Institute of Chemical Engineers; [date unknown]. [accessed 2019 Mar 13]. https://www.aiche.org/community/students/career-resources-k-12-students-parents/what-do-chemical-engineers-do. |
| ++ Online database | 17. Agency for Toxic Substances and Disease Registry (ATSDR). ATSDR Toxicological Profile Information Sheet database [Internet]. U. S. Dept. of Health and Human Services, Centers for Disease Control and Prevention (CDC). [accessed 2019 Mar 13]. https://www.atsdr.cdc.gov/toxprofiles/index.asp. |
| ++ AI (Artificial Intelligence) | 24. OpenAI (2024). Discussion on biochemistry topics [ChatGPT model]. OpenAI. [accessed 2024 Sep 9]. https://www.openai.com/chatgpt. |
Note: This is an example of an integrated list of all references.
1. Prinn RG. Atmospheric ozone. In McGraw-Hill encyclopedia of science and technology. 7th ed. Vol. 2. New York: McGraw-Hill; 1992. p. 229-232.
2. Uretsky S, Davidson T. Antacids. In: Gale encyclopedia of medicine [database on the Internet]. 5th ed. Vol. 1. Farmington Hills (MI): Gale; 2015. [accessed 2019 Mar 13]. (Gale Virtual Reference Library). p 274-276. https://go.galegroup.com/ps/start.do?p=GVRL.
3. Uretsky S, Davidson AMT, Longe JL. Antacids. In: Gale encyclopedia of medicine [database on the Internet]. 3rd ed. Detroit (MI): Thomson Gale; 2006. [accessed 2009 Oct 22]. (Health Reference Center Academic). [about 2 p.]. http://find.galegroup.com/gtx/start.do?prodId=HRCA.
4. National Research Council. Ozone-forming potential of reformulated gasoline. Washington (DC): National Academy Press; 1999. 212 p.
5. McCuen GE, editor. Our endangered atmosphere: global warming and the ozone layer. Hudson (WI): Gary E. McCuen Publications; 1987. 133 p.
6. Rigos G, Nengas I, Alexis M, Troisi GM. Potential drug (oxytetracycline and oxolinic acid) pollution from Mediterranean sparid fish farms [abstract]. Aquatic Toxicology. 2004 Aug 25;69(3):281-8. In: PubMed [database on the Internet]. Washington (DC): NLM [accessed 2019 Mar 13]. https://www.ncbi.nlm.nih.gov/entrez/.
7. William P. The ozone below. Audubon. 1994 Sep-Oct;96(5):14, 22-23.
8. Browne MW. Antarctica's ozone layer is threatened by depletion. NY Times. 1994 Oct 8;Sect A:7(col 6).
9. Brasseur GP, Prinn RG. Stratospheric ozone. In AccessScience @ McGraw-Hill: encyclopedia of science and technology online [database on the Internet]. 2007-19 ed. [New York]: McGraw-Hill; 2018. [accessed 2019 Mar 13]. https://www.accessscience.com/.
10. Andersen S, Sarma K. Protecting the ozone layer: the United Nations history. London: Earthscan Publications; 2002. 400 p.
11. Young CT and updated by staff. Nuts. In: Kirk-Othmer encyclopedia of chemical technology [database on the Internet]. 1999-2019 ed. Hoboken (NJ): Wiley; 2007. [accessed 2019 Mar 13]. https://onlinelibrary.wiley.com/doi/book/10.1002/0471238961.
12. Chiuchiolo AL, Dickhut RM, Cochran MA, Ducklow HW. Persistent organic pollutants at the base of the Antarctic marine food web. Environmental Science & Technology. 2004;38(13):3551-3557. In: Academic Search Complete [database on the Internet]. Ipswich (MA): EBSCO [accessed 2006 Sep 5]. 7 p. http://search.ebscohost.com/.
13. Chiuchiolo AL, Dickhut RM, Cochran MA, Ducklow HW. Persistent organic pollutants at the base of the Antarctic marine food web. Environmental Science & Technology. 2004;38(13):3551-3557. In: American Chemical Society Publications: Journals and Magazines [database on the Internet]. Washington (DC): ACS; c2000-2019 [accessed 2019 Mar 13]. https://pubs.acs.org/about.html.
14. Mackenzie D. Anybody want to save the ozone layer? In: Gribbin J, editor. The breathing planet. New York: Basil Blackwell; 1986. p. 185-192.
15. Bekki S, Law KS, Pyle JA. Effect of ozone depletion on atmospheric CH(4) and CO concentrations. Nature. 1994 Oct 13;371(6498):595-597.
16. Careers in chemical engineering - what do chemical engineers do? [Internet]. New York (NY): American Institute of Chemical Engineers; [date unknown]. [accessed 2012 Oct 22]. https://www.aiche.org/community/students/career-resources-k-12-students-parents/what-do-chemical-engineers-do.
17. Agency for Toxic Substances and Disease Registry (ATSDR). ATSDR Toxicological Profile Information Sheet database [Internet]. U. S. Dept. of Health and Human Services, Centers for Disease Control and Prevention (CDC). [accessed 2019 Mar 13]. https://www.atsdr.cdc.gov/toxprofiles/index.asp.
18. Can we save the ozone layer? [place unknown]: Concerned Citizen Press; [date unknown].
19. Pulford I. Environmental chemistry at a glance. Oxford; Malden (MA): Blackwell Pub.; 2006. 132 p.
20. Brody J. Cutting cholesterol, an uphill battle. The New York Times [Internet]. 2007 Aug 21. [accessed 2007 Sep 27]. http://www.nytimes.com/2007/08/21/health/21brod.html?_r=1&oref=slogin.
21. Travis J. Toxin trumped. Science News. 2002 Aug 17:99. In: Academic Search Complete [database on the Internet]. Ipswich (MA): EBSCO [accessed 2019 Mar 19]. https://search.ebscohost.com/.
22. Neidle S. Principles of nucleic acid structure [electronic resource] . Amsterdam: Elsevier; Boston: Academic Press; 2008. [accessed 2019 Mar 13]. https://www.ebscohost.com/ebooks/home.
23. Luster M, Simeonova P, Germolec D. Immunotoxicology. In: Encyclopedia of life sciences [database on the Internet]. 1999-2013 ed. Hoboken (NJ): Wiley; 2008. [accessed 2013 Feb 20]. http://onlinelibrary.wiley.com/mrw/advanced/search?doi=10.1002/047001590X.
24. OpenAI. (2024). Discussion on biochemistry topics [ChatGPT model]. OpenAI. [accessed 2024 Sep 9]. https://www.openai.com/chatgpt.