1. D.K. Brown, Ph.D. Thesis, Pennsylvania State University, in preparation.
2. Linear Operators Part I;Dunford,1963
3. Some systems of second order arithmetic and their use;Friedman,1975
4. Systems of second order arithmetic with restricted induction (abstracts);Friedman;J. Symbolic Logic,1976
5. A finite combinatorial principle which is equivalent to the 1-consistency of predicative analysis;Friedman,1982