1. Planar Graphs;Whitney;Fund. Math.,1933
2. Introductory Circuit Theory;Guillemin,1953
3. On Cut-Sets of Electric Networks;Seshu,1956
4. On Max-Flow Min-Cut Theorem of Networks in Linear Inequalities;Dantzig;Annals Math. Studies,1956
5. The Application of Graph Theory to the Synthesis of Contact Networks;Gould,1957