The Critical Archive
Christopher Hollings, Ursula Martin, and Adrian Rice. "The Lovelace-De Morgan mathematical correspondence: a critical re-appraisal," Historia Mathematica, Vol. 44 (August 2017), no. 3, 202--231.
A Selection and Adaptation From Ada's Notes
Martin, Ursula. "Ada Lovelace, mathematician", Math. Today (Southend-on-Sea) 51 (2015), no. 6, 254
Angluin, Dana. "Lady Lovelace and the Analytical Engine," AWM Newsletter, Vol. 6, No. 1 (January 1976), 5-10, and Vol. 6, No. 2 (February 1976), 6-8. [Reprinted in Complexities: Women in Mathematics, Bettye Anne Case and Anne Leggett, Editors, Princeton University Press (2005), 60-67.]