Terminal value problem for singular ordinary differential equations: theoretical analysis and numerical simulations of ground states. Palamides, Alex P., Yannopoulos, Theodoros G. (2006) Boundary Value Problems [electronic only]
The distribution of nonprincipal eigenvalues of singular second-order linear ordinary differential equations. Pinasco, Juan Pablo (2006) International Journal of Mathematics and Mathematical Sciences
Two modifications of the Leggett-Williams fixed point theorem and their applications. Mavridis, Kyriakos G. (2010) Electronic Journal of Differential Equations (EJDE) [electronic only]