Doxygen \cite producing empty bibliography

I was facing the same problem. There is an perl dependency to generate citation. So you must have both perl and bibtex in the system path.

Ignore the example above, that only applies to Latex, for doxygen use (Note: no braces):

\cite Hale

The .bib file has to be located in doxygen working directory.

Bibliographic References HTML page will be then produced by doxygen with:

[1]J. K. Hale. Theory of functional–differential equations. Springer–Verlag, Berlin–Heidelberg–New York, 1977.

for the following bib entry:

   @BOOK{Hale,
   author = "J. K. Hale",
   title = "Theory of functional--differential equations",
   publisher = "Springer--Verlag, Berlin--Heidelberg--New York",
   year = 1977
   }