Menger algebras of $n$-place functions
  It is a survey of the main results on abstract characterizations of algebras of $n$-place functions obtained in the last 40 years. A special attention is paid to those algebras of $n$-place functions which are strongly connected with groups and semigroups, and to algebras of functions closed with respect natural relations defined on their domains. 
Wieslaw A. Dudek and Valentin S. Trokhimenko
math.RA