1. The structure of free abelian l-groups and free vector lattices

   • Michael R. Darnel

   OriginalPaper Pages: 99 - 110

2. Interpolation and the Robinson property for logics not closed under the Boolean operations

   • H. Ono

   OriginalPaper Pages: 111 - 122

3. Free products of near-rings and their modules

   • J. D. P. Meldrum

   OriginalPaper Pages: 123 - 131

4. Lattice varieties covering V(L₁)

   • J. B. Nation

   OriginalPaper Pages: 132 - 166

5. Equational bases for some varieties of orthomodular lattices related to states

   • René Mayet

   OriginalPaper Pages: 167 - 195

6. Varieties of lattice-ordered groups in which prime powers commute

   • W. Charles Holland
   • Alan H. Mekler
   • Norman R. Reilly

   OriginalPaper Pages: 196 - 214