P. Sathishmohan, V. Rajendran, and P.K. Dhanasekaran. “Further Properties of Nano Pre- $T_0$, Nano Pre- $T_1$ and Nano Pre- $T_2$ Spaces”. Malaya Journal of Matematik, vol. 7, no. 01, Jan. 2019, pp. 34-38, doi:10.26637/MJM0701/0007.