Preface:Special issue dedicated to Professor Gaston M. N’Gu´er´ekata on the occasion of his 60th birthday. Nonlinear Studies, [S. l.], v. 20, n. 2, 2013. Disponível em: https://nonlinearstudies.com/index.php/nonlinear/article/view/850. Acesso em: 15 jan. 2025.