Turtles and defense. - Patrick Sobalvarro; Leigh Klotz (SIGART Newsl., 1982)

Bridging the paper and electronic worlds: the paper user interface. - Walter Johnson; Herbert D. Jellinek; Leigh Klotz; Ramana Rao; Stuart K. Card (INTERCHI, 1993)

Protofoil: storing and finding the information worker's paper documents in an electronic file cabinet. - Ramana Rao; Stuart K. Card; Walter Johnson; Leigh Klotz; Randall H. Trigg (CHI Conference Companion, 1994)