P. Ehlen, M. Johnston, и G. Vasireddy. Proceedings of ICSLP---Interspeech 2002: 7th International Conference on Spoken Language Processing, Denver, CO, USA, стр. 2557-2560. (2002)
S. Au Yeung, и M. Siu. Proceedings of Interspeech 2004---ICSLP: 8th International Conference on Spoken Language Processing, Jeju Island, Korea, стр. 161-164. (2004)