Haihui Zhang
      A note on vertex arboricity of toroidal graphs without 7-cycles
      International Mathematical Forum, Vol. 11, 2016, no. 14, 679-686
      http://dx.doi.org/10.12988/imf.2016.6672

Copyright © 2016 Haihui Zhang. This article is distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.