What does et al. mean?
Often seen in reference lists for a variety of different styles, et al. is a common abbreviation from the Latin "et alia" (gender neutral), "et alii" (masculine), or "et aliae" (feminine). It means "and others", or "and all the rest".
When is it used?
Et al. is used with a very long list of authors to indicate that there are more contributors not specifically listed. While the ACS Style Guide generally recommends listing all authors (Chapter 14, page 291), some journals ask for only a certain number of listed authors before using et al., so check the requirements of the publication.
Where is the punctuation?
Since only "alia" is abbreviated, it gets the period. Putting the period after "et" is a common mistake.
This Grammarly post does an illustrated explanation.
Style 1 - Superscript numbers ***this style is used in CHEM 4160 with Dr. Ray***
Example 1 Oscillation in the reaction of benzaldehyde with oxygen was reported previously.3
Example 2 Frink3 reported oscillation in the reaction of benzaldehyde with oxygen.
References are numbered according to the order you cite them. The first reference you cite is 1, the second is 2, etc. If you use the same reference multiple times, use the same superscript number every time.
Style 2 - Italic numbers
Example 1 Oscillation in the reaction of benzaldehyde with oxygen was reported previously (3).
Example 2 Frink (3) reported oscillation in the reaction of benzaldehyde with oxygen.
Style 3 - Author-date system
Example 1 Oscillation in the reaction of benzaldehyde with oxygen was reported previously (Frink et al., 2005).
Example 2 Oscillation in the reaction of benzaldehyde with oxygen was reported previously by Frink and colleagues (2005).
For in text citations for items with:
Two authors - provide the last name of both authors, separated by the word "and"
(Nahasapeemapetilon and Alenno, 2005).
More than two authors - provide the last name of only the first author listed, and then "et al."
(Mollman et al., 2012).
Collect all references at the end of the manuscript...
Author 1; Author 2; Author 3; etc. Title of Article. Journal Abbreviation Year, Volume (Issue), Inclusive Pagination.
Caruso, R.A.; Susha, A.; Caruso, F. Multilayered Titania, Silica, and Laponite Nanoparticle Coatings on Polystyrene Colloidal Templates and Resulting Inorganic Hollow Spheres. Chem. Mater. 2001, 13, 400-409.
- Bold for year, italic for journal title and issue number
- Use the CASSI abbreviation for the journal title
- Capitalize all main words in the article title (excluding connecting words like "and", "or", "on", etc.)
Patent Owner 1; Patent Owner 2; etc. Title of Patent. Patent Number, Date.
Sheem, S. K. Low-Cost Fiber Optic Pressure Sensor. U.S. Patent 6,738,537, May 18, 2004.
Author (if any). Title of Site. URL (accessed Month Day, Year).
ACS Publications Division Home Page. http://pubs.acs.org (accessed Nov 7, 2017).
- Include the date you accessed a website, since websites often change over time
Author 1; Author 2; Author 3; etc. Book Title, Edition Number; Series Information (if exists); Publisher: Place of Publication, Year; Volume Number, Pagination.
Nakamoto, K. Infrared and Raman Spectra of Inorganic and Coordination Compounds, 6th ed.; Wiley: Hoboken, NJ, 2009; pp 23-32.
- Italics for book title, but year is not bolded (different from journal article)
- pages are indicated with "pp" (different from journal article)
Book Chapter (from an edited book)
Nishiyama, H.; Shiomi, T. Reductive Aldol, Michael, and Mannich Reactions. In Metal Catalyzed Reductive C-C Bond Formation : A Departure from Preformed Organometallic Reagents; Krische, M.J., Ed.; Springer: Berlin, 2007; pp 105-138.
Ghosh, A. Arrow Pushing in Inorganic Chemistry: A Logical Approach to the Chemistry of the Main-Group Elements. John Wiley & Sons, Incorporated: Hoboken, NJ, 2014: pp 201. http://site.ebrary.com/lib/gastate/detail.action?docID=10902334 (accessed January 5, 2017).