APA-ийн эшлэл(7 дахь хэвлэлт)

(1992). Extensions of logic programming: Second international workshop, Stockholm, Sweden, January 27-29, 1991, proceedings / L.-H. Eriksson, L. Hallnäs, P. Schroeder-Heister (eds.).

Чикаго-гийн эшлэл (17 дахь хэвлэлт)

Extensions of Logic Programming: Second International Workshop, Stockholm, Sweden, January 27-29, 1991, Proceedings / L.-H. Eriksson, L. Hallnäs, P. Schroeder-Heister (eds.). 1992.

MLA -ийн эшлэл (9 дэх хэвлэлт)

Extensions of Logic Programming: Second International Workshop, Stockholm, Sweden, January 27-29, 1991, Proceedings / L.-H. Eriksson, L. Hallnäs, P. Schroeder-Heister (eds.). 1992.