A Discretely Adaptive Delta Modulation Codec. - Kunihiko Niwa; Akira Yukawa; Atsushi Tomozawa (IEEE Trans. Commun., 1981)

An oversampling A-to-D converter structure for VLSI digital codec's. - Akira Yukawa; Rikio Maruta; Kenji Nakayama (ICASSP, 1985)

A stable high-order delta-sigma modulator with an FIR spectrum distributor. - Toshiyuki Okamoto; Yuichi Maruyama; Akira Yukawa (IEEE J. Solid State Circuits, 1993)

Special Section on Analog Circuit Techniques and Related Topics. - Akira Yukawa (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2006)