References in the text should be cited in one of three ways:
1. By superscript numbers, which appear outside the punctuation if the citation applies to a whole sentence or clause.
Oscillation in the reaction of benzaldehyde with oxygen was reported previously.3
2. By italic numbers in parentheses on the line of text and inside the punctuation.
The mineralization of TCE by a pure culture of a methane-oxidizing organism has been reported (6).
3. By author name and year of publication in parentheses inside the punctuation (known as author–date).
The primary structure of this enzyme has also been determined (Finnegan et al., 2004).
Cite the reference in a logical place in the sentence.
References should be numbered sequentially. If a reference is cited more than once, it does not receive a new number, use the original reference number. If citing more than one reference at a time, include reference numbers in increasing order separated by commas (without spaces as superscripts, with spaces on line) or use an en dash to indicate a range of three or more.
When citing more than one reference at one place by the author–date system, list them alphabetically according to the first author’s name, followed by a comma and the year. Use a semicolon to separate individual references. When citing more than one reference by the same author at one place by the author–date system, do not repeat the name. List the name followed by the year of each of the references in ascending order; separate the years by commas. If an author has more than one reference in the same year, add lowercase letters to the years to differentiate them.
In all three systems, the author’s name may be made part of the sentence. In such cases, in the author–date system, place only the year in parentheses.
The syntheses described by Fraser8 take advantage of carbohydrate topology.
Jensen (3) reported oscillation in the reaction of benzaldehyde with oxygen.
According to Harris (2003), drug release is controlled by varying the hydrolytic stability of the ester bond.
Whenever authors are named, if a reference has two authors, give both names joined by the word “and”. If a reference has more than two authors, give only the first name listed, followed by “et al.” Do not use a comma before et al.; always use a period after al.
Allison and Perez12
Johnson et al. (12)
(O’Brien and Alenno, 2005)
(Bachrach et al., 2004)
Author 1; Author 2; Author 3; etc. Title of Article. Journal Abbreviation Year, Volume, Inclusive Pagination.
Include all author names in a reference citation. With multiple authors, separate the names from one another by semicolons. Always end the author field with a period. List the names in inverted form: surname first, then first initial, middle initial, and qualifiers (Jr., II). Some publications list the first 10 authors followed by a semicolon and et al.
Article titles are not mandatory. Article titles are set in roman type without quotation marks and end with a period (or a question mark if that is part of the title). Capitalization follows that of the original publication or the main words are capitalized.
Abbreviate the journal name according to CASSI (Chemical Abstracts Service Source Index). One-word journal names are not abbreviated (e.g., Biochemistry, Macromolecules, Nature, Science). No punctuation is added to end this field; thus, a period will be there with an abbreviation but not with a spelled-out word.
Year of Publication
The year is set in boldface type, followed by a comma in boldface type.
The volume number is set in italic type and is separated from the pagination information by a comma, which is set in italic type.
For periodicals in which each issue begins with page 1, include issue information (either the number or the date) in the publication volume field. Issue information is set in roman type, enclosed in parentheses, and spaced from the volume number, which it directly follows.
Mullin, R. Chem. Eng. News 2005, 83 (42), 7.
Date of Issue:
Mullin, R. Chem. Eng. News 2005, 83 (Oct 17), 7.
For publications that have supplements, the following form is recommended.
Taylor, C. W.; Kumar, S. Eur. J. Cancer 2005, 40 (Suppl. 1), 781. Eur. J. Anaesthesiol. 2005, 22 (Suppl. S36), 1–35.
For journals that have no volume numbers, include issue numbers, especially when the pagination of each issue begins with page 1. Use the following form. The issue number is not italicized.
Wills, M. R.; Savory, J. Lancet 1983, No. 2, 29.
The complete page range is preferable, but initial page numbers are acceptable. In page spans, use all digits, closed up, with no commas or spaces. Some publications use article numbering, rather than page numbering, where each article starts on page 1 include the article number.
Nonscientific Magazines and Newspapers
Author 1; Author 2; Author 3; etc. Title of Article. Title of Periodical, Complete Date, Pagination.
Give the authors’ names in inverted form ending with a period, the article title in roman type with main words capitalized and ending with a period, the full magazine title in italic type followed by a comma in italic type, the complete date of the issue (see pp 160–161 about dates) ending with a comma, and the pagination.
Author (if any). Title of Site. URL (accessed Month Day, Year), other identifying information (if any).
Use the title found on the Web site itself; add the words “Home Page” for clarification when needed. Data retrieved from Internet-based databases should include a data entry number. Stand-alone databases should be cited as computer programs.
If an article is contained within a large and complex Web site, such as that for a university or a government agency, the host organization and the relevant program or department should be identified before giving the direct URL of the article and accession date.
Based on Print Editions
Author 1; Author 2; Author 3; etc. Title of Article. Journal Abbreviation [Online] Year, Volume, Inclusive pagination or other identifying information. URL (accessed Month Day, Year).
Author 1; Author 2; Author 3; etc. Title of Article. Journal Abbreviation [Online] Year, Volume, Article Number or other identifying information. URL (accessed Month Day, Year).
Author 1; Author 2; Author 3; etc. Book Title [Online]; Series Information (if any); Publisher: Place of Publication, Year; Volume Number, Pagination. URL (accessed Month Day, Year).
Author 1; Author 2; Author 3; etc. Chapter Title. In Book Title [Online]; Editor 1, Editor 2, etc., Eds.; Series Information (if any); Publisher: Place of Publication, Year; Volume Number, Pagination. URL (accessed Month Day, Year).
References to computer programs must be treated on a case-by-case basis. Five common presentations of computer programs are possible:
1. Book format, with the name of the program as the title
Author 1; Author 2; etc. Program Title, version or edition; Publisher: Place of Publication, Year.
2. Technical Report format
Author. Title of Report; Technical Report Number; Publisher: Place of Publication, Year; Pagination (if any).
3. CASSI format
Johnson, C. K. Oak Ridge Natl. Lab., [Rep.] ORNL (U.S.) 1978, ORNL-5348
4. Free style, as a simple listing of program title and author of program
When only minimal information (e.g., author and program name) is available, present the information as simply as possible.
Programs used in this study included local modifications of Jacobson’s ALLS, Zalkins’s FORDAP, Busing and Levy’s ORFEE, and Johnson’s ORTEP2.
5. Thesis style
Sheldrick, G. M. SHELX-76: Program for Crystal Structure Determination. Cambridge University, 1976.
Hard copy (paper) MSDS
Titanium Dioxide; MSDS No. T3627; Mallinckrodt Baker: Phillipsburg, NJ, November 12, 2003.
MSDS obtained from an Internet search
Titanium Dioxide; MSDS No. T3627 [Online]; Mallinckrodt Baker: Phillipsburg, NJ, November 12, 2003.http://www.jtbaker.com/msds/englishhtml/t3627.htm (accessed 4/15/08).
MSDS obtained from a database source such as CCOHS
Titanium Dioxide; MSDS No. T3627 [Online]; Mallinckrodt Baker: Phillipsburg, NJ, November 12, 2003. Available from Canadian Centre for Occupational Health and Safety. http://website.com (accessed 4/15/14).