Anatoli Degtyarev Yuri Gurevich Paliath Narendran Margus Veanes Andrei Voronkov The Decidability of Simultaneous Rigid <i>E</i>-Unification with One Variable. 181-195 http://dx.doi.org/10.1007/BFb0052370 1998 conf/rta/1998 RTA db/conf/rta/rta98.html#DegtyarevGNVV98