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COMPUTATIONAL COMPLEXITY, 3 (3)., pp. 245-261.
Baltzer, Basel, pp. 83-106.
ACTA CYBERNETICA, 10 (3)., pp. 217-220.
COMPUTATIONAL COMPLEXITY, 2 (3)., pp. 225-243.
MATEMATIKAI LAPOK, 2 (3-4)., pp. 1-22.
SIAM JOURNAL ON DISCRETE MATHEMATICS, 5 (3)., pp. 345-365.
LECTURE NOTES IN COMPUTER SCIENCE, 646, pp. 71-85.
JPTE, Pécs