1. Burnell, D. G.,Left cancellative semigroups and an embedding problem, Doctoral Dissertation, University of California, Davis, 1970.
2. Clifford, A. H. and G. B. Preston,The algebraic theory of semigroups, Vol. I, Survey 7, Amer. Math. Soc., Providence, R.I., 1967.
3. —,The algebraic theory of semigroups, Vol. II, Amer. Math. Soc., Providence, R.I., 1967.
4. Dragunova, T. E.,The lattice of right ideals of left cancellative semigroups with identity, Usp. Mat. Nauk 12 (1957), 285–288 (in Russian).
5. Petrich, M.,Introduction to semigroups, Vol. II (in preparation).