@ARTICLE{BurDasHarLau_j1985, author = {Gustav~Burosch and J{\"u}rgen~Dassow and Walter~Harnau and Dietlinde~Lau}, title = {On subalgebras of an algebra of predicates}, journal = eikalt, year = 1985, volume = 21, number = {}, pages = {9--22} }