Essential extensions and radical classes of lattice-ordered groups Yuehui ZhangJinhe Wei Original Paper Pages: 401 - 406
\(\mathcal{P}\mathcal{A}{\text{-isomorphisms}}\) of inverse semigroups Simon M. Goberstein Original Paper Pages: 407 - 432
Congruence properties in congruence permutable and in ideal determined varieties, with applications. C. J. van. Alten Original Paper Pages: 433 - 449
Congruence preserving functions of Wilke’s tree algebras Saeed Salehi Original Paper Pages: 451 - 470
