"[PDF] nMOS reversible energy recovery logic for ultra-low-energy ...." 1 Jun. 2000, https://www.semanticscholar.org/paper/nMOS-reversible-energy-recovery-logic-for-Lim-Kim/c4bd39b46201585217984ea56abe0ea321b81a76. https://web1.eng.famu.fsu.edu/~mpf/CF05/talks/Kim.ppt