J.P. Costa

On ideals of a skew lattice

M. Steinby

On the solidity of general varieties of tree languages

A. Borumand Saeid, M. Faisal Nadeem, N. Yaqoob

Some results in bipolar-valued fuzzy ordered AG-groupoids

I. Trendafilov

Derivations in some finite endomorphism semirings

K. Denecke, Y. Susanti

On sets related to maximal clones

K. Denecke, P. Jampachon, Y. Susanti

Four-part semigroups - semigroups of Boolean operations