1. É. A. Asratyan, Zh. Vyssh. Nerv. Deyat.,23, No. 2, 262 (1973).
2. É. A. Asratyan, Reflex Theory and the Problem of Motivation. Basic Problems in Electrophysiology of the Brain [in Russian], Nauka, Moscow (1974), p. 5.
3. É. A. Asratyan, Essays on Higher Nervous Activity [in Russian], Izd. Akad. Nauk Arm. SSR, Erevan (1977).
4. I. P. Pavlov, Twenty Years of Experience of Objective Study of the Higher Nervous Activity (Behavior) of Animals [in Russian], Nauka, Moscow (1973).
5. B. K. Anand, in: Regulation of Nervous Drives in Feeding Behavior. Totus Homo, Vol. 3 (1971), p. 59.