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2. G. S. Pisarenko et al., Vibration-Absorbing Properties of Construction Materials [in Russian], Naukova Dumka, Kiev (1971).
3. D. L. Smith, A. L. Vinitski, and R. G. Lee, ?Automatic instrument for measuring internal friction,? Test Instruments and Stands, No. 45 (1970).
4. P. A. Grandamp and R. K. Fornerod, ?Automatic device for measuring the elastic constants and losses to internal friction in specimens of material,? Test Instruments and Stands, No. 22 (1970).
5. G. V. Becker, ?Automation of test devices for recording mechanical relaxation of materials,? Test Instruments and Stands, No. 20 (1970).