G. Sethuraman, M. Sujasree, A. Velankanni
      Gracefulness of graphs obtained from vertex duplication
      International Journal of Mathematical Analysis, Vol. 10, 2016, no. 18, 863-873
      http://dx.doi.org/10.12988/ijma.2016.6684

Copyright © 2015 G. Sethuraman, M. Sujasree and A. Velankanni. 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.