Severino V. Gervacio, Hiroshi Maehara, Joselito A. Uy
      On the span and extent of unit-distance graphs in the plane
      Applied Mathematical Sciences, Vol. 10, 2016, no. 33, 1611-1618
      http://dx.doi.org/10.12988/ams.2016.512728

Copyright © 2015 Severino V. Gervacio, Hiroshi Maehara and Joselito A. Uy. 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.