1. F. Harary, The cell growth problem and its attempted solutions,Beiträge zur Graphentheorie (Int. Koll. Manebach, 9–12. Mai 1967), ed. H. Sachs, H.—J. Voss, and H. Walther. B. G. Teubner Verlagsgesellschaft Leipzig 1968, 49–60.
2. J. E. Hopcroft andR. M. Karp, An 5/2 algorithm for maximum matchings in bipartite graphs,SIAM J. Comput. 2 (1973) 225–231.
3. E. L. Lawler,Combinatorial Optimization: Networks and Matroids, Holt, Rinehart and Winston, New York, 1976.