1. Bennett, C., Sharpley, R.: Interpolation of Operators. Academic Press, Boston (1988)
2. Bogveradze, G., Castro, L.P.: On the Fredholm index of matrix Wiener–Hopf plus/minus Hankel operators with semi-almost periodic symbols. Oper. Theor. Adv. Appl. 181, 143–158 (2008)
3. Böttcher, A., Grudsky, S.M., Spitkovsky, I.M.: The spectrum is discontinuous on the manifold of Toeplitz operators. Arch. Math. 75, 46–52 (2000)
4. Böttcher, A., Grudsky, S.M., Spitkovsky, I.M.: Toeplitz operators with frequency modulated semi-almost periodic symbols. J. Fourier Anal. Appl. 7, 523–535 (2001)
5. Böttcher, A., Grudsky, S.M., Spitkovsky, I.M.: On the essential spectrum of Toeplitz operators with semi-almost periodic symbols. Oper. Theor. Adv. Appl. 142, 59–77 (2003)