Richard M. Karp. Reducibility Among Combinatorial Problems(PDF). R. E. Miller; J. W. Thatcher (编). Complexity of Computer Computations. New York: Plenum. 1972: 85–103 [2023-06-07]. (原始内容(PDF)存档于2011-06-29).
Richard M. Karp. Reducibility Among Combinatorial Problems(PDF). R. E. Miller; J. W. Thatcher (编). Complexity of Computer Computations. New York: Plenum. 1972: 85–103 [2023-06-07]. (原始内容(PDF)存档于2011-06-29).