Anand Rangarajan Alan L. Yuille Steven Gold Eric Mjolsness A Convergence Proof for the Softassign Quadratic Assignment Algorithm. 620-626 http://nips.djvuzone.org/djvu/nips09/0620.djvu 1996 conf/nips/1996N NIPS db/conf/nips/nipsN1996.html#RangarajanYGM96