When citing a paper with a lot of authors; is it OK to shorten the author list in the references section? I want to cite a paper that has a lot of authors. The list of authors take up half a page in my reference list, and considering the prospect of paying for extra pages, I would like to shorten it, if possible. Is is okay to shorten the author list? If so, how many authors should be included?
Every citation style has some threshold at which it is OK to change a long list into an "et al." citation ("et al." is an abbreviation of the Latin "et alia" meaning "and others").  The particular threshold depends on the citation style, but if you've got half a page of authors it's certainly over any reasonable threshold.

You then simply convert your citation of, e.g.:


  A, B, C, E, ... , Z, "Massive Joint Study," Journal of Big Science, 1(4), 2012.


into:


  A, et al., "Massive Joint Study," Journal of Big Science, 1(4), 2012.