1. Uch. Zap. Mosk. Gos. Univ. No. 75, Bk. 2, Pt. 2;Krasnushkin;On waves in curved tubes,1945
2. Radiotekhnika i Elektrouika;Seveshnikov;Waves in bent tubes,1958
3. Akustische Zeitschrift;Grigor'yan;Theory of sound wave propagation in curvilinear wave guides,1969
4. National College for Heating, Ventilating, Refrigeration and Fan Engineering Technical Memo. No. 5;Osborne;The propagation of sound waves round a bend of rectangular section,1968