1. R.Arundhathi and V.Ilayarani, “Total coloring of closed helm, flower and bistar graph family,” International Journal of Scientific and Research Publications 7, 616 (2017).
2. B.J.Balamurugan, K.Thirusangu, and D. Thomas, “Strongly multiplicative zumkeller labeling of graphs,” Int. Conf. Inf. Math. Sci., 349–354 (2013).
3. Algorithms for Zumkeller Labeling of Full Binary Trees and Square Grids
4. B. J. Balamurugan and R. M. Meenakshi, “Zumkeller labeling of complete graphs,” International Journal of Engineering and Advanced Technology (IJEAT) ISSN: 2249 – 8958 9 (2019).
5. e. S. Clark, “Zumkeller numbers,” presented in the Mathematical Abundance Conference at Illinois State University on April 18th, 2008.