Reference:

Matti Varjokallio, Mikko Kurimo, and Sami Virpioja. Learning a subword vocabulary based on unigram likelihood. In Proceedings of the IEEE Automatic Speech Recognition and Understanding Workshop (ASRU 2013), 2013.

Suggested BibTeX entry:

@inproceedings{varjokallio2013asru,
    author = {Matti Varjokallio and Mikko Kurimo and Sami Virpioja},
    booktitle = {Proceedings of the IEEE Automatic Speech Recognition and Understanding Workshop (ASRU 2013)},
    language = {eng},
    title = {Learning a Subword Vocabulary Based on Unigram Likelihood},
    year = {2013},
}