Harmonic morphisms of graphs and the Riemann-Hurwitz theorem

Mednykh, Alexander, 1953-

Harmonic morphisms of graphs and the Riemann-Hurwitz theorem / A. D. Mednykh, Roman Nedela

In Doklady Mathematics. -- Moscow : Pleiades Publishing, 2016. -- ISSN 1064-5624. -- ISSN 1531-8362. -- Vol. 93, no. 1 (2016), pp. 23-26