1.
Kelevedjiev P, Popivanov N. EXISTENCE OF SOLUTIONS OF BOUNDARY VALUE PROBLEMS FOR THE EQUATION $f(t,x,x’,x’’) = 0$ WITH FULLY NONLINEAR BOUNDARY CONDITIONS. Ann. Sofia Univ. Fac. Math. and Inf. [Internet]. 2002 Dec. 12 [cited 2024 Nov. 22];94:55-70. Available from: https://annual.uni-sofia.bg/index.php/fmi/article/view/190