A shortest path from me to Paul Erdős is:

T. Sun → J. L. Gross
→ F. Harary
→ P. Erdős

via the papers
- Genus distributions of cubic series-parallel graphs
- J. L. Gross, M. Kotrbčik, T. Sun,
*Discrete Math. and Theoretical Comp. Sci. 16(3) (2014)* - Some problems in topological graph theory
- J. L. Gross, F. Harary,
*J. Graph Theory 4(3) (1980)* - On the dimension of a graph
- P. Erdős, F. Harary, W. T. Tutte,
*Mathematika 12(2) (1965)*