Preface:Special issue dedicated to Professor Gaston M. N’Gu´er´ekata on the occasion of his 60th birthday

Abstract

This special issue contains papers prepared by colleagues, friends, and students of Professor N'Gu\'er\'ekata's, and closely related to his research areas. It is a great pleasure and honor to present the special issue of the Nonlinear Studies dedicated to Professor Gaston Mandata N'Gu\'er\'ekata to the reader.