The package enables the user to make reference to "division
marks" (such as book, chapter, section), in the document being
referenced, in addition to the page-based references that
BibTeX-based citations have always had. The citation is made in
the same way as the LaTeX standard, but what's inside the
square brackets may include the "division" specification, as in
\cite[(<division spec.>)<page number>]{<document>}
