The crossing number of the complete 4-partite graph $K_{1,1,m,n}$

Xiwu Yang, Ni Lu, Xiaodong Chen +1

Let $\text{cr}(G)$ denote the crossing number of a graph $G$. The well-known Zarankiewicz's conjecture (ZC) asserted $\text{cr}(K_{m,n})$ in 1954. In 1971, Harborth gave a conj…