Generalized Function Algebras and PDEs with Singularities. A Survey. Marko Nedeljkov, Stevan Pilipović (2006) Zbornik Radova
Generalized n-dimensional Gronwall's inequality and its applications to non-selfadjoint and non-linear hyperbolic equations Sudhanshu K. Ghoshal, Abha Ghoshal, M. Abu-Masood (1977) Annales Polonici Mathematici