On the closure of ${\{e^{ { {i\lambda}_n} x}\}}$, I On the closure of ${\{e^{ { {i\lambda}_n} x}\}}$, II Zeros of entire functions of exponential type On non-harmonic Fourier series Fourier transforms of nonvanishing functions A density theorem of Polya Determination of the rate of growth of analytic functions from their growth on sequences of points An inequality and functions of zero type existence of functions of zero-type bounded on a sequence of points The general higher indices theorem The general unrestricted Tauberian theorem for larger gaps On restrictions necessary for certain higher indices theorems Appendix.