The role of F0 and duration in signalling affect in Japanese: anger, kindness and Politeness. - Etsuko Ofuka; Hélène Valbret; Mitch G. Waterman; Nick Campbell 001; Peter Roach (ICSLP, 1994)

Prosodic cues for rated politeness in Japanese speech. - Etsuko Ofuka; J. Denis McKeown; Mitch G. Waterman; Peter J. Roach (Speech Commun., 2000)