Kandala, R. R., D. Singh, and F. Wang. “Design of a 2X2 Reading and Writing Array for Programmable Metallization Cell”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 27, no. 3, June 2016, pp. 89-101, https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/5849.