Jiro Tanaka Kazunori Ueda Tashihiko Miyazaki Akikazu Takeuchi Yuji Matsumoto Koichi Furukawa Guarded Horn Clauses and Experience with Parallel Logic Programming. 948-954 1986 conf/fjcc/1986 FJCC db/conf/fjcc/fjcc86.html#TanakaUMTMF86