Varieties of (unary) semigroups, a selection
L.P., On varieties of completely regular semigroups I,
Semigroup
Forum 32, 97-123 (1985)
J. Kaďourek & L.P., On the word problem for free completely regular
semigroups,
Semigroup Forum 34, 127-138 (1986)
L.P., On varieties of completely regular semigroups II, Semigroup Forum
36,
No.3, 253-284 (1987)
L.P., On varieties of completely regular semigroups III, Semigroup
Forum
37, No.1, 1-30 (1988)
J. Kaďourek & L.P., On free semigroups satisfying x^r = x ,
Simon
Stevin 64, No.1, 3-19 (1990)
L.P., Structural theorems for varieties of bands, Lattices,
semigroups,and
universal algebra, Proc. Int. Conf., Lisbon/Port. 1988, 211-223 (1990)
L.P., Free regular unary semigroups, Rhodes, John (ed.), Monoids and
semigroups
with applications. Proceedings of the Berkeley workshop in monoids,
Berkeley
(USA) 1989, World Scientific Publishing, Singapore, 184-197 (1991)
L.P., A multiplication on the lattice of varieties of *-regular
semigroups,
Bonzini, C. (ed.) et al., Semigroups: algebraic theory and applications
to
formal languages and codes. Proceedings of the international
conference
on semigroups, Luino (Italy) 1992, World Scientific
Publishing,
Singapore, 231-245, (1993)
M. Kuřil & L.P., On varieties
of semilattice-ordered semigroups, Semigroup Forum 71 (2005), no 1,
27-48, (c)
Springer-Verlag