Correa, V. H. G. ., R. A. da S. Braga, D. B. . Karolak, and F. R. Silva. “A Subthreshold Biased CMOS Ring Oscillator Model Design in 180-Nm Process”. Journal of ICT Research and Applications, vol. 17, no. 2, Aug. 2023, pp. 135-50, doi:10.5614/itbj.ict.res.appl.2023.17.2.1.