BibTeX FilesDue to the format of the BibTeX file, the standard
VIM tools for text search lead to suboptimal results. There
are several tools around that facilitate searching BibTeX
files. If you want a GUI, you could use, e.g., the java-based

JabRef
– be aware though that JabRef usually resorts your
BibTeX files.
The VIM plugin tbibtools, provides a command
:TBibList that creates a browsable list of the
BibTeX entries including the entry’s ID, its title,
its authors or editors, as well as the entry’s keywords.
tbibtools includes a ruby-based command-line
tool that can be used to sort or merge BibTeX files.
You can use VIM plugins like ttoc to get a
quick overview of the entries contained in the BibTeX file
opened in the current buffer.