1. G. E. Andrews, The Theory of Partitions, Encyclopedia of Mathematics and its Applications, vol. 2, Cambridge University Press (Cambridge, 1998)
2. L. M. Blumenthal, Theory and Applications of Distance Geometry, Clarendon Press (Oxford, 1953)
3. Clifford, A.H., Preston, G.B.: The Algebraic Theory of Semigroups, Part 1, Mathematical Surveys and Monographs, vol. 7. RI, AMS (Providence (1961)
4. Dovgoshey, O.: Semigroups generated by partitions. Int. Electron. J. Algebra 26, 145–190 (2019)
5. Dovgoshey, O., Petrov, E.: Weak similarities of metric and semimetric spaces. Acta Math. Hungar. 141, 301–319 (2013)