Group-supermagic labeling of Cartesian products of two even cycles

A Γ-supermagic labeling of a graph G=(V,E) with |E|=q is a bijection from E to an Abelian group Γ of order q such that the sum of labels of all incident edges of every vertex x∈V is equal to the same element μ∈Γ. An existence of a Γ-supermagic labeling of Cartesian product of two cycles C_m□C_n for every m,n≥3 by Z_2mn and for any two odd cycles C_m□C_n for any m,n≥3 and any Abelian group Γ of order 2mn was proved recently. In this paper we completely solve the case of m,n both even and present a labeling method for all Abelian groups of order 2mn, where m,n are even and greater than two.