1. Lower bounds for the low hierarchy;Allender;Journal of the ACM,1992
2. Relativizations of the P=? NP question;Baker;SIAM Journal on Computing,1975
3. Separating, strongly separating, and collapsing relativized complexity classes;Balcázar,1984
4. Sparse sets, lowness and highness;Balcázar;SIAM Journal on Computing,1986
5. Structural Complexity I;Balcázar,1988