1. On representatives of subsets;Hall;J. London Math. Soc.,1935
2. Lectures on Ergodic Theory;Halmos,1956
3. A precomposition analysis of linear operators on lp;Hudson,1991
4. Transversals of infinite set systems;Milner;Ann. New York Acad. Sci.,1979
5. Transversal Theory;Mirsky,1971