@article{GDZPPN001252623,
title = {Inverse semigroup varieties with the amalgamation property.},
journal = {Semigroup forum},
volume = {16},
year = {1978},
pages = {37-52},
zbl = {0396.20039},
url = {http://dml.mathdoc.fr/item/GDZPPN001252623}
}
Hall, T.E. Inverse semigroup varieties with the amalgamation property.. Semigroup forum, Tome 16 (1978) pp. 37-52. http://gdmltest.u-ga.fr/item/GDZPPN001252623/