David Shallcross Victor Y. Pan Yu Lin-Kriz Planar Integer Linear Programming is NC Equivalent to Euclidean GCD. 960-971 1998 27 SIAM J. Comput. 4 db/journals/siamcomp/siamcomp27.html#ShallcrossPL98 http://dx.doi.org/10.1137/S0097539794276841