Intani, P., C. Anyapo, C. Phondon, and T. Comedang. “Low Power Ring Oscillator Using VTCMOS”. Journal of Advanced Development in Engineering and Science, vol. 4, no. 9, Aug. 2023, pp. 11-24, https://ph03.tci-thaijo.org/index.php/pitjournal/article/view/814.