bibtex-read-key
bibtex-read-key is a compiled Lisp function in `bibtex.el
'.
(bibtex-read-key PROMPT &optional KEY GLOBAL)
Read BibTeX key from minibuffer using PROMPT and default KEY.
If optional arg GLOBAL is non-nil, completion is based on the keys in
`bibtex-reference-keys' of `bibtex-files',