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Semigroups with few endomorphisms. preprint, submitted to Australian Journal of Math.
MR 0245706
[2] Z. HEDRLÍN J. LAMBEK:
How comprehensive is the category of semigroups. preprint, submitted to Journal of Algebra.
MR 0237611
[3] A. PULTR:
Eine Bemerkung über volle Einbettungen von Kategorien von Algebren. submitted to Mathematische Annalen.
Zbl 0174.30002