CoCoA is a computer algebra system for doing computations in Commutative Algebra. Please also cite the algorithms listed at http://cocoa.dima.unige.it/citing.html
Citation:
@Misc{CocoaSystem,
author = {{CoCoA}Team},
title = {{{\hbox{\rm C\kern-.13em o\kern-.07em C\kern-.13em o\kern-.15em A}}}: a system for doi\
ng {C}omputations in {C}ommutative {A}lgebra},
howpublished ={Available at \/ {\tt http://cocoa.dima.unige.it}},
}