@unpublished{icfp2021b,
 author = {M. Maleki and
           B. A. Pearlmutter and
           J. M. Siskind},
 title = {Adding AD to Scheme by differentiation the Interpreter},
 location = {ICFP Scheme and Functional Programming Workshop},
 date = 27,
 month = aug,
 year = 2021,
 url = {http://engineering.purdue.edu/~qobi/tweet-talks/icfp2021b-slides.pdf}}