1. Odashima, et al, ϵ-separating nonlinear digital filter, I.E.C.E., 1981-Conference Records, 1260.
2. ϵ-separating nonlinear digital filter and its applications;Harashima;I.E.C.E., Trans. (A),1982
3. On nonlinear filters involving transformation of the time variable;Moore;I.E.E.E. Trans. Inform. Theory,1973
4. Application of a nonlinear smoothing algorithm to speech processing;Rabiner;I.E.E.E. Trans. Acoust. Speech, Sig. Process.,1975
5. Odashima, et al, Theoretical analysis of ϵ-separating filters-their nonlinear characteristics and multi-stage design, I.E.C.E., 1981 Information System Conference Records, 22.