Multi-variate block polar quantization and applications to audioPobloth, H.; Vafin, Renat; Kleijn, W.B.Proc IEEE Int. Conf. Acoustics, Speech, Signal Processing : ICASSP 2004 : Montreal, Canada, 2004. Vol. 42004 / p. 197-200 https://ieeexplore.ieee.org/document/1326797

Towards optimal quantization in multistage audio codingVafin, Renat; Kleijn, W.B.Proc IEEE Int. Conf. Acoustics, Speech, Signal Processing : ICASSP 2004 : Montreal, Canada, 2004. Vol. 42004 / p. 205-208