Muthuramalingam, Pl. “Spectral Properties of Vaguely Elliptic Pseudo Differential Operators With Momentum Dependent Long Range Potentials Using Time Dependent Scattering Theory - II”. MATHEMATICA SCANDINAVICA 58 (June 1, 1986): 255–274. Accessed November 24, 2024. https://www.mscand.dk/article/view/12145.