1. Transmission systems for communications.;Bell,1971
2. Bennett, W.R. (1940) Cross modulation requirements on multichannel amplifiers below overload, Bell Systems Technical Journal, (19) October.
3. CCITT(1985) Volume III, CCITT, Geneva.
4. Introductory topics in electronics and telecommunications –- Noise;Connor,1973
5. Holbrook, B.D. and Dixon, J.T. (1939) Load rating theory for multichannel amplifiers, Bell Systems Technical Journal, (18), October.