@article{DBLP:journals/ijac/RhodesS01,
author = {John Rhodes and
Benjamin Steinberg},
title = {Profinite Semigroups, Varieties, Expansions and the Structure
of Relatively Free Profinite Semigroups},
journal = {IJAC},
volume = {11},
number = {6},
year = {2001},
pages = {627-672},
ee = {http://dx.doi.org/10.1142/S0218196701000784},
bibsource = {DBLP, http://dblp.uni-trier.de}
}