We consider the following question: how large does n have to be to guarantee that in any two-colouring of the edges of the complete graph Kn,n there is a monochromatic Kk,k? In th...
For d 1, s 0 a (d,d +s)-graph is a graph whose degrees all lie in the interval {d,d +1,...,d +s}. For r 1, a 0 an (r,r+1)-factor of a graph G is a spanning (r,r+a)-subgraph of...
We consider the question of characterizing Pfaffian graphs. We exhibit an infinite family of non-Pfaffian graphs minimal with respect to the matching minor relation. This is in sha...