Kawahara, Hideki; Masuda-Katsuse, Ikuyo; de Cheveigné, Alain (abril de 1999). «Restructuring speech representations using a pitch-adaptive time–frequency smoothing and an instantaneous-frequency-based F0 extraction: Possible role of a repetitive structure in sounds». Speech Communication (em inglês). 27 (3–4): 187–207. doi:10.1016/S0167-6393(98)00085-5