D. Perry, and W. Evangelist. Proceedings of the Twentieth Annual Hawaii International Conference on Systems Sciences, Vol II, page 113--126. (January 1987)
R. Knapp, and P. Cook. Proceedings of the International Computer Music Conference, page 4--9. Barcelona, Spain, L'Escola Superior de Música de Catalunya, (5--9 September 2005)
G. Wang, and P. Cook. Proceedings of the International Conference on New Interfaces for Musical Expression, page 138--143. National University of Singapore, (2004)