1. The polynomial-time hierarchy;Stockmeyer;Theoret. Comput. Sci.,1976
2. Relativizations of the P=?NP question;Baker;SIAM J. Comput.,1975
3. The complexity of theorem-proving procedures;Cook,1971
4. Completeness in the polynomial-time hierarchy: Part I: A compendium;Schaefer;ACM SIGACT News,2002
5. Completeness in the polynomial-time hierarchy: Part II: A compendium;Schaefer;ACM SIGACT News,2002