1. C. Dimitracopoulos, Doctorial thesis, Manchester. To appear.
2. J. Ketonen & R. Solovay, "Rapidly growing Ramsey functions", to appear.
3. L. Kirby, "Initial segments of models of arithmetic", Doctorial thesis, Manchester, 1977.
4. L. Kirby & J. Paris, "Initial segments of models of Peano’s axioms". Springer-Verlag lecture notes in mathematics, Vol. 619.
5. G. Mills, "Extensions of models of Peano arithmetic" Doctorial thesis, Berkeley, 1977.