P. Sathishmohan, V. Rajendran, and P.K. Dhanasekaran. 2019. “Further Properties of Nano Pre- $T_0$, Nano Pre- $T_1$ and Nano Pre- $T_2$ Spaces”. Malaya Journal of Matematik 7 (01). India:34-38. https://doi.org/10.26637/MJM0701/0007.