BibTeX doesn't accept spaces in the name of the bibliography file it inputs. So a file named
A B C.bib is rejected.
It's by no means necessary that the
.bib file has the same name as the LaTeX file; to the contrary, many people organize their big bibliography file and call that one for all their papers.
Example. The following is the file
You process it by saying
and it's BibTeX's job to read from
naji.aux the line
so it can open for reading the file
najibibdatabase and extract from it the entries corresponding to the
There's no requirement that the argument to
\bibliography is the same name as the main TeX file where it's given.
In any case it's best to avoid spaces in file names for all TeX-related documents.