ÇELEBİ, A. Okay2019-04-222019-04-221303-6009http://hdl.handle.net/20.500.12575/61439https://doi.org/10.1501/commua1-2_0000000022Vekua's Method for Solving the Equation ... and a Cauchy Problem for an Ultrahyperbolic Equation139142