H. Traunmüller. Experiments in speech processes, volume XII of Phonetic Experimental Research at the Institute of Linguistics, The Institute of Linguistics, University of Stockholm, Stockholm, (1991)
C. Danescu-Niculescu-Mizil, R. West, D. Jurafsky, J. Leskovec, and C. Potts. Proceedings of the 22nd international conference on World Wide Web, page 307--318. Republic and Canton of Geneva, Switzerland, International World Wide Web Conferences Steering Committee, (2013)
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)