W. Cavnar, and J. Trenkle. Proceedings of SDAIR-94, 3rd Annual Symposium on Document Analysis and Information Retrieval, page 161--175. Las Vegas, US, (1994)
S. Feldman, M. Marin, M. Ostendorf, and M. Gupta. Proceedings of the 2009 IEEE International Conference on Acoustics, Speech and Signal Processing, page 4781--4784. Washington, DC, USA, IEEE Computer Society, (2009)