1. The fundamental representation of a regular semigroup;Clifford,1975
2. The Algebraic Theory of Semigroups;Clifford,1961
3. Biordered sets are biordered subsets of idempotents of semigroups;Easdown;J. Austral. Math. Soc.,1984
4. A new proof that regular biordered sets come from regular semigroups;Easdown,1984
5. D. Easdown, Fundamental semigroups and biordered sets, in preparation.