F. Knop. (2005)cite arxiv:math/0506171
Comment: v1: 24 pages; v2: 31 pages, expanded exposition, new introduction,
some facts (esp. Thm. 7.2+Corollaries, Thm. 8.4) which were only implicit in
v1 are now spelled out.
G. Tzimiropoulos, N. Mitianoudis, and T. Stathaki. Acoustics, Speech and Signal Processing, 2007. ICASSP 2007. IEEE International Conference on, 1, page I-785 -I-788. (15-20 2007)
L. Jilani, O. Mraihi, A. Louhichi, W. Ghardallou, and A. Mili. ICSE '10: Proceedings of the 32nd ACM/IEEE International Conference on Software Engineering, page 317--318. New York, NY, USA, ACM, (2010)