Efficient Multilingual Phoneme-to-Grapheme Conversion Based on HMM Panagiotis A Rentzepopoulos author George K Kokkinakis author 1996 text journal article Computational Linguistics continuing MIT Press Cambridge, MA periodical academic journal rentzepopoulos-kokkinakis-1996-efficient https://aclanthology.org/J96-3003/ 1996 22 3 351 376