1. Bergman, G. M.,Actions of Boolean rings on sets, Algebra Universalis (to appear).
2. Bergman, G. M.,Connected components of inverse images, (to be written, title tentative).
3. Bergman, G. M. andHausknecht, A. O.,Co-[abelian groups] and Co-rings in Categories of Associative Rings, (book in preparation; draft of currently completed material, � 0?45, 185 pp.,available from first author).
4. Bredon, G.,Sheaf Theory, McGraw-Hill Series in Higher Mathematics, 1967.
5. Clifford, A. H. andPreston, G. B.,The Algebraic Theory of Semigroups. American Mathematical Society Mathematics Surveys 7, (1961).