P. Lam, J. Liu, W. Shiu and J. Wu, “Some Sufficient Conditions for a Planar Graph to Be of Class 1,” Congressus Numerantium, Vol. 136, No. 4, 1999, pp. 201- 205.

has been cited by the following article:

• TITLE: Edge Colorings of Planar Graphs without 6-Cycles with Two Chords

  AUTHORS: Ling Xue, Jianliang Wu

  KEYWORDS: Edge Coloring; Planar Graph; Cycle; Class 1

  JOURNAL NAME: Open Journal of Discrete Mathematics, Vol.3 No.2, April 25, 2013

  ABSTRACT: It is proved here that if a planar graph has maximum degree at least 6 and any 6-cycle contains at most one chord, then it is of class 1.