1. P. Heitkämper: Optimization of an acoustic echo canceller combined with adaptive gain control, Proc. ICASSP-95, Detroit, Michigan, 1995, pp. 3047–3050
2. J. Marx: Akustische Aspekte der Echokompensation in Freisprecheinrichtungen, VDI-Fortschritt-Berichte, Reihe 10, Nr. 400, Düsseldorf, 1996
3. R. Frenzel: Freisprechen in gestörter Umgebung, VDI-Fortschritt-Berichte, Reihe 10, Nr. 228, Düsseldorf, Germany, 1992
4. S. Yamamoto, S. Kitayama: An Adaptive Echo Canceller with Variable Step Gain Method, Trans. IECE of Japan vol. E 65, no. 1, 1982, pp. 1–8.
5. International Telecommunication Union: General characteristics of international telephone connections and international telephone circuits — acoustic echo controllers. ITU-T Recommendation G.167, 1993.