Proper Bibtex Author Field Syntax For Multiple Authors

The Problem: Confusion Over Comma and Ampersand Usage

When creating a BibTeX entry for a source with multiple authors, it can be confusing to know when to use commas and when to use ampersands (&) to separate the author names. Improper usage of these punctuation marks leads to errors that prevent your bibliography from generating correctly.

This article clarifies the correct syntax for listing multiple author names across the most common situations. Proper comma and ampersand usage for BibTeX author fields will be explained through code examples and guidelines.

BibTeX Author Field Overview

The BibTeX author field contains the names of the authors of the source being referenced. Author names in this field must be formatted according to BibTeX's expectations.

Allowed Author Name Formats

Individual author names within the author field should be written as:

• Lastname, Firstname
• Lastname, Firstname Initial
• Lastname, F. M. (for multiple first name initials)

Let's see some code examples of how single and multiple author names should appear.

Code Examples for Single vs. Multiple Authors

Single Author

@book{singleton,
  author = {Knuth, Donald},
  title = {The Art of Computer Programming},
  year = {1968}
}

Two Authors

@book{doubleton,
  author = {Lamport, Leslie and LaTEX, LaTeX}, 
  title = {LaTeX User's Guide},
  year = {1986}
}  

Three Authors

 
@book{tripleton,
  author = {Nelson, Ted and Neumann, John Von and Wood, William},
  title = {How to Build a Computer},
  year = {1955}
}

Handling Two Authors

When listing two author names in a BibTeX entry, an ampersand (&) should be used between them. Here are the key details:

Correct Format: Lastname1 & Lastname2

@book{twoauthors,
  author = {Doe, John & Smith, Jane},
  ...
}

• No spaces around the ampersand
• Comma after the first last name
• Ampersand directly before the second last name

Common Mistakes to Avoid

These forms of two author names should NOT be used:

// Wrong!
Doe, John and Smith, Jane  

// Wrong!
Doe, John & Smith, Jane

// Wrong! 
Doe, John Smith, Jane

Remember, the ampersand always directly connects the two last names with no space on either side.

Handling Three or More Authors

The rules change slightly when listing three or more author names in BibTeX.

Correct Format: Lastname1, Lastname2 & Lastname3

@book{threepersons,
  author = {Doe, John, Smith, Jane & Thompson, Tim},
  ... 
}

• Commas separate first and second authors
• Ampersand before the final author name

When to Use Commas vs. Ampersands

Remembering when to use commas and ampersands can be tricky with multiple authors:

• Commas go between first and middle authors
• Ampersand always directly precedes the final author

For example, if there were four authors the format would be:

Lastname1, Lastname2, Lastname3 & Lastname4

Special Cases

Let's discuss some special name formats you may encounter.

Authors with Multiple Middle Names or Initials

If an author has multiple middle names or initials, list them all with spaces between initials:

  
@book{specialauthor,
  author = {Doe, John D. M. & Smith, Jane Y. F.},
  ...
}

Authors with Particles in Their Names

Some authors have name particles like "de" or "van" as part of their last names. Include these when formatting the name:

@book{particles,
  author = {De Gaulle, Charles & Van Owens, Franz},
  ...
} 

Checking Your Entries

Use these tactics to catch author field errors:

Linting Tools

BibTeX linters automatically check for improper formatting and invalid entries:

• bibclean
• Latexmk
• textlint

Manual Inspection

Also visually inspect each author field that you create or modify:

1. Verify comma use between all but last author
2. Verify ampersand directly precedes final author
3. Check for consistency in name capitalization
4. Look for incorrect name particle handling

Recap and Summary

Handling author names properly is vital for generating accurate bibliographies from BibTeX. Remember these key points:

• Use Lastname, Firstname format
• Separate two authors with a comma and ampersand
• Use commas between early names and ampersand before the last for three+ authors
• Account for subtle name formats like particles and multiple initials
• Lint and visually inspect your BibTeX author fields

Following the name format, punctuation, and verification steps outlined here will help avoid issues when citing sources with multiple authors.