bibtex-validate is an interactive compiled Lisp function in `
(bibtex-validate &optional TEST-THOROUGHLY)
Validate if buffer or region is syntactically correct.
Check also for duplicate keys and correct sort order provided
`bibtex-maintain-sorted-entries' is non-nil.
With optional argument TEST-THOROUGHLY non-nil check also for
the absence of required fields and for questionable month fields.
If mark is active, validate current region, if not the whole buffer.
Only check known entry types, so you can put comments outside of entries.
Return t if test was successful, nil otherwise.