EXISTENCE OF SOLUTIONS OF BOUNDARY VALUE PROBLEMS FOR THE EQUATION $f(t,x,x’,x’’) = 0$ WITH FULLY NONLINEAR BOUNDARY CONDITIONS. Annual of Sofia University St. Kliment Ohridski. Faculty of Mathematics and Informatics, [S. l.], v. 94, p. 55–70, 2002. Disponível em: https://annual.uni-sofia.bg/index.php/fmi/article/view/190. Acesso em: 14 dec. 2025.