Covers and packings in a family of sets

[1]  D. R. Fulkerson,et al.  Widths and heights of (0,1)-matrices. , 1961 .

[2]  R. Z. Norman,et al.  An algorithm for a minimum cover of a graph , 1959 .

[3]  J. Roth.  Algebraic topological methods for the synthesis of switching systems. I , 1958 .

[4]  C. Berge.  Théorie des graphes et ses applications , 1958 .

[5]  C Berge,et al.  TWO THEOREMS IN GRAPH THEORY. , 1957, Proceedings of the National Academy of Sciences of the United States of America.