1. Day, G.W.: Superatomic Boolean algebras. Pac. J. Math.23, 479?489 (1967)
2. Dobbertin, H.: Verfeinerungsmonoide, Vaught Monoide und Boolesche Algebren. Dissertation, Universität Hannover, 1983
3. Dobbertin, H.: On Vaught's criterion for isomorphisms of countable Boolean algebras. Algebra Univ.15, 95?114 (1982)
4. Dobbertin, H.: Primely generated regular refinement monoids. J. Algebra (to appear)
5. Hanf, W.: Primitive Boolean algebras. In: Proc. Symp. Pure Math. (Proceedings of the Tarski Symposium, Berkeley, California, 1971), No. 25, pp. 75?90. Providence, R.I.: AMS 1974