Researchr is a web site for finding, collecting, sharing, and reviewing scientific publications, for researchers by researchers.
Sign up for an account to create a profile with publication list, tag and review your related work, and share bibliographies with your co-authors.
Sartaj Sahni, Ellis Horowitz. Combinatorial Problems: Reductibility and Approximation. Operations Research, 26(5):718-759, 1978. [doi]
Abstract is missing.