How to cite an answer in StackExchange?

There is a link at the bottom that provides a citation in bibtex or amsrefs format;

Clicking on this particular link the bibtex citation generated is;

@MISC {58756, TITLE = {Unique ways to keep N balls into K Boxes?}, AUTHOR = {Gjergji Zaimi (https://math.stackexchange.com/users/14274/gjergji-zaimi)}, HOWPUBLISHED = {Mathematics Stack Exchange}, NOTE = {URL:https://math.stackexchange.com/q/58756 (version: 2011-08-21)}, EPRINT = {https://math.stackexchange.com/q/58756}, URL = {https://math.stackexchange.com/q/58756} }

You could put that in your .bib file. From that point, it really depends how the rest of your citations are being formated. You might get something like;

That seems like a pretty standardised way to do it.

Here is another, more specific example:

Over on Mathematica.SE a rewrite of a minimization algorithm to save computational time helped the OP of this question to complete some data analysis and publish a paper. The reimplementation was cited in the paper as Ref. 35.