Joseph A. Paradiso, Che King Leo, Nisha Checka, Kaijen Hsiao. Passive acoustic knock tracking for interactive windows. In Loren G. Terveen, Dennis R. Wixon, editors, Extended abstracts of the 2002 Conference on Human Factors in Computing Systems, CHI 2002, Minneapolis, Minnesota, USA, April 20-25, 2002. pages 732-733, ACM, 2002. [doi]
Abstract is missing.