A long-term predictive ADPCM coder with short-term prediction and vector quantization. - Alv I. Aarskog; Arild Nilsen; Ole Berg; Hans C. Guren (ICASSP, 1991)

Predictive coding of speech using microphone/speaker adaptation and vector quantization. - Alv I. Aarskog; Hans C. Guren (IEEE Trans. Speech Audio Process., 1994)