Bibliography:


Classification and Regression Trees , L. Breiman, J. H. Friedman, R. A. Olshen and C. J. Stone, Monterey, CA, Wadsworth, 1984.


"A Tree-Based Statistical Language Model for Natural Language Speech Recognition", L. Bahl, P. Brown, P. deSouza and R. Mercer, IEEE Transcation on Acoustics, Speech and Signal Processing , volume 37, pages 1001--1008, 1989.