1. Advanced Problem 5082, proposed by the Junior Research Seminar for High School students of Summer 1962,1963
2. Polynomial identities;Amitsur;Israel J. Math.,1974
3. The index of a group in a semigroup;Bergman;Pacific J. Math.,1971
4. Modules over coproducts of rings;Bergman;Trans. Amer. Math. Soc.,1974
5. Coproducts, and some universal ring constructions;Bergman;Trans. Amer. Math. Soc.,1974