J. Murphy, B. Booth, M. Collins, G. Harris, D. Sexton, и M. Webb. Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, 365 (1857):
1993--2028(15.08.2007)
S. Vilkomir, D. Parnas, V. Mendiratta, и E. Murphy. Proceedings of the 29th Australasian Computer Science Conference - Volume 48, стр. 55--61. Darlinghurst, Australia, Australia, Australian Computer Society, Inc., (2006)