Paths in Graphs and Curves on Surfaces
Alexander Schrijver · Birkhäuser Basel eBooks · 1994
A classical result in graph theory due to the topologist Menger [24] concerns the existence of pairwise internally vertex-disjoint paths connecting two given vertices r and s in an undirected graph G = (V, E). (Two paths are internally vertex-disjoint if they do not have any vertex or edge in common, except for the end vertices.)