1. Inhomogeneities in the polynomial time degrees;Ambos-Spies;Inform. Process. Lett.,1986
2. Minimal pairs for polynomial time reducibility;Ambos-Spies,1987
3. The theory of polynomial many-one degrees of recursive sets in undecidable;Ambos-Spies,1992
4. Honest polynomial-time degrees of elementary recursive sets;Ambos-Spies,1990
5. Relativizations of the Ptime=? NP question;Baker;SIAM J. Comput.,1975