@Book{zbMATH03179521,
Author = {A. H. {Clifford} and G. B. {Preston}},
Title = {{The algebraic theory of semigroups. Vol. I.}},
FJournal = {{Mathematical Surveys}},
Journal = {{Math. Surv.}},
ISSN = {0076-5376},
Volume = {7},
Year = {1961},
Publisher = {American Mathematical Society (AMS), Providence, RI},
Language = {English},
MSC2010 = {20Mxx 20-01 20-02},
Zbl = {0111.03403}
}