T. D. Cong, T. L. Thanh, P. T. T. Bao, and T. Hoang "A Novel Approach to Design a Process Design Kit Digital for CMOS 180nm Technology", Advances in Science, Technology and Engineering Systems Journal, vol. 6, no. 1, pp. 1191–1198, 2021, doi: 10.25046/aj0601135.