1. Baskakov, S.I., Radiotekhnicheskie tsepi i signaly: Uchebnik dlya vuzov po spetsial’nosti “Radiotekhnika” (Radio Engineering Chains and Signals: A Manual of Radio Engineering), Moscow: Vysshaya Shkola, 2003.
2. Blumstein, D.T, Social Complexity but not the Acoustic Environment Is Responsible for the Evolution of Complex Alarm Communication, Adaptive strategies and diversity in marmots, Ramousse, R., Allaine, D., and Berre, M., Eds., Lyon: Intern. Marmot Network, 2003, pp. 31–38.
3. Bogatyrev, Yu.K., Amplitude Modulation, Fizicheskaya entsiklopediya (Physical Encyclopedia), Moscow: Sov. entsiklopediya, 1988, vol. 1, pp. 71–72.
4. Darden, S.K., Pedersen, S.H., and Dabelsteen, T., Methods of Frequency Analysis of a Complex Mammalian Vocalisation, Bioacoustics, 2003, vol. 13, pp. 247–263.
5. Magnus, K., Kolebaniya: Vvedenie v issledovanie kolebatel’nykh sistem (Oscillations: Introduction to Investigation of Oscillatory Systems), Moscow: Mir, 1982.