1. Avdonin, S.A.: On Riesz bases of exponentials in L 2. Vestn. Leningr. Univ. Math. 7, 203–211 (1979)
2. Avdonin, S.A., Belinskiy, B.P.: Controllability of a string under tension. Dyn. Syst. Differ. Equ. (Ext. Vol.) 57–67 (2003)
3. Avdonin, S.A., Belinskiy, B.P.: On the basis properties of the functions arising in the boundary control problem of a string with a variable tension. Discrete Contin. Dyn. Syst. (Suppl. Vol.) 40–49 (2005)
4. Avdonin, S.A., Belinskiy, B.P.: On controllability of a rotating string. J. Math. Anal. Appl. 321, 198–212 (2006)
5. Avdonin, S.A., Ivanov, S.A.: Families of Exponentials. The Method of Moments in Controllability Problems for Distributed Parameter Systems. Cambridge University Press, Cambridge (1995)