JabRef is an open-source cross-plotform software for managing scientific references. Mendeley is a good cost-free cross-platform software for managing scientific references. It introduces the concept of social research.

If you use bibtex in your LaTeX code, you have to compile your code using pdflatex/latex, bibtex, pdflatex/latex and pdflatex/latex in sequence.

natbib is a LaTeX package for citing references, and it is compatible with bibtex.

If you use author and date style references and there are duplicate authors and years, natbib print out the whole list of names and years by default instead of using abbreviation for names. To avoid this problem, you can add letters to the end of years. (not sure about this ...)

The \eqref command is convenient way to reference equations in LaTeX.