On Absolute a-summability factors
A Theorem on the Geometric Mean of an Entire Function
Helmholtz Equation and WKB Approximation in the Tidal wawe Propagation
Radii of Valence of Certain Analytic Functions with Negative Coefficients
The Interior and Exterior Problems For The Generalized Poly-Axially Symmetric Helmholtz Equation
Comparison and Oscillation Theorems for singular Ultrahyperbolic Equations