1. On Imbedding Graphs in the Sphere;Auslander;J. Math. Mech.,1961
2. The Concept of Uniform Branch Multiplicity in Graphs;Bedrosian;Nachrtech. Z.,1964
3. On Straight Line Representation of Planar Graphs;Fary;Acta sci. math. Szeged,1948
4. A.J. Goldstein, “An Efficient and Constructive Algorithm for Testing whether a Graph can be imbedded in the Plane”, Bell Teleph. Labs Rep. (unpublished).
5. Analytic Inequalities;Kazarinoff,1961