I'd like to cite sage-matroid. I have the following BibTeX, ripped off from the one that Sages gives out:
Any changes/comments?
@manual{sage-matroid,
Author = {Rudi Pendavingh and Stefan {Van Zwam} and others},
Date-Modified = {2013-07-18 23:23:01 +0000},
Key = {Sage},
Note = {{\tt
http://www.sagemath.org}},
Organization = {The Sage Matroid Development Team},
Title = {{S}age {M}atroid {Package}, included in {S}age {M}athematics {S}oftware 5.11},
Year = {2013}}