Bisemilattice-valued fuzzy sets. Lazarević, Vera, Šešelja, Branimir, Tepavčević, Andreja (1998) Novi Sad Journal of Mathematics
Bivariate function algebras on Posets. David A. Smith (1971) Journal für die reine und angewandte Mathematik
Brouwerian semilattices: The lattice of total subalgebras Peter Köhler (1982) Banach Center Publications