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>}
