When citing sources with three to five authors, name all of them the first time and use "et al." only in future cites. Use "et al." from the first citation for sources with six or more authors. (Note: When writing articles, it is customary to list authors last name first.)
So, how many authors before you use et al? The correct answer is from three to five authors, you use their names individually. If there are six or more authors, you use their names together as one group called "et al."
Authors used to be listed alphabetically but now they are usually listed by title.
Examples: John Smith, Jane Doe; John Smith, Mary Baker; Joe Public, Sophie Anne.
Citing multiple authors with three or more names will always result in "and others," because you cannot identify each author's contribution without listing them all together. For example: Carter, Davis, and Green.
Authors used to be listed according to what role they played in the argument or study but now they are usually just listed alphabetically.
Examples: John Smith; Jane Doe; Joe Public; Sophie Anne.
If there are at least six writers, use "et al." from the first mention. In all circumstances, use the first author's last name followed by "et al." in your in-text citation.
How to Apply Etc.
In every reference, including the first, use simply the first author's name followed by "et al." unless doing so would cause uncertainty between distinct sources. Et should not be followed by a period in et al. Only the word "al" should be separated by a period. Authors' names are all found in the Bibliography or Reference section of this document.
Et also stands for et sexagesimum annum (the last six digits of any year). This is used when citing statistics such as frequencies and percentages.
As well as being used after an author's name, et can also be used at the end of a sentence to indicate that someone other than the speaker is responsible for the statement: "It was John who told us about the party, not Mary." It is placed before the noun it modifies: "The book et its author are both available from the library".
Finally, et can also be used as an adverb meaning "also": "I read a book, a play, et a film".
The word "et" has various uses in science, especially biology. In mathematics, physics, and chemistry, it is employed when giving a list of multiple items.
When a book has more than two authors or fewer than six authors, cite all of them the first time the reference appears; in subsequent cites, add just the first author's last name, "et al.", and the year. For instance, (Miller, Richardson, Hoag, and Zalud, 1994) is referenced for the first time. It will be cited again in a journal article by adding "and others" after Miller et al and including the citation information from the original reference.
Books with more than six authors are too large for most journals to publish. These books can be divided into groups based on what role each author played in writing or publishing the book. For example, if one author was responsible for creating most of the material in the book while another edited, wrote introductions, etc., then these authors would be considered joint first authors. If there are only two authors, they must be listed as such in any reference list or bibliography.
Journals that accept articles with more than three authors may require you to break up the work into several articles or remove one or more authors from the list. Often, the extra authors are included in an acknowledgments section at the end of the paper.
A work written by three or more authors In every reference, including the first, use simply the first author's name followed by "et al." unless doing so would cause uncertainty between distinct sources. Authors' names are usually printed in alphabetical order, so this will make it easier to locate them.
If the work was published in book form, the title of which includes the words "editor" or "editors", then each editor should be listed as an author. If there is only one editor, he or she can be listed with another word such as "compiler" to indicate that they have compiled the work.
In some cases, people other than authors may need to be included as authors. For example, if a book has two co-authors who do not share writing credit, they should be listed as separate authors. A book may also have many contributors, such as when several people help write an article or prepare illustrations for its pages. These individuals too should be listed as authors.
Finally, in some cases, editors and others involved in preparing material but not writers themselves may be given authorship credits. For example, a book editor may be credited as "senior editor". When listing authors, it is important to identify all persons who have contributed significantly to the publication.
If there are three or more writers, list just the first, followed by the phrase et al. (Latin for "and others") in lieu of the names of the remaining authors. Et alia is used when there are more than two but not so many that it's impractical to list them all. Authors' last names should be listed in alphabetical order.
In general, use et al. as a way of saying "and others" when there are additional contributors beyond those included on the list. When writing about famous people, it is usual to include their fields of expertise in addition to their names. For example, if Thomas Edison invented the phonograph, it would be correct to say that he et al. developed the phonograph.
There are several ways to indicate that one author has contributed equally to a project. The simplest method is to list them both with the word et al. In some cases, only their surnames will appear together; for example, John Smith and Michael Brown might be written as John Smith et al. or Michael Brown et al.
If you want to specify that two authors have an equal contribution, then they must be listed in the text as such.