1) Theodorsen, T.: Genaral Theory of Aerodynamic Instability and the Mechanism of Flutter, NACA Report 496, 1935, pp. 2–21. (This paper is also included in A Modern View of Theodore Theodorsen published by AIAA in 1992.)
2) Kármán, Th. Von and Sears, W. R.: Airfoil Theory for Non-Uniform Motion, J. Aeronaut. Sci., 5 (1938), pp. 379–390.
3) Schwarz, Von L.: Berechnung der Druckverteilung einer Harmonisch Sich Verformenden Trag Fläche in Ebener Strömung, Luftfahrtforschung, 17, 11 & 12 (1940), pp. 379–386.
4) Tomonari, Y.: Extended Theodorsen Function for an Airfoil with a Wake, Trans. Jpn. Soc. Aeronat. Space Sci., 45 (2003), pp.229–235.
5) Bisplinghoff, R. L., Ashley, H. and Halfman, R. L.: Aeroelasticity, second printing, Addison-Wesley Publishing Co., Inc., Massachusetts, 1957, pp. 251–277.