Young R.M. An Introduction to Non-Harmonic Fourier Series

New York: Academic Press, 2001. - 249 p.An Introduction to Non-Harmonic Fourier Series, Revised Edition is an update of a widely known and highly respected classic textbook.
Throughout the book, material has also been added on recent developments, including stability theory, the frame radius, and applications to signal analysis and the control of partial differential equations.