Wc. Lian et al., ON THE EXISTENCE OF POSITIVE SOLUTIONS OF NONLINEAR 2ND-ORDER DIFFERENTIAL-EQUATIONS, Proceedings of the American Mathematical Society, 124(4), 1996, pp. 1117-1126
Under suitable conditions on f(t, u), the boundary value problem [GRAP
HICS] has at least one positive solution. Moreover, we also apply this
main result to establish several existence theorems of multiple posit
ive solutions for some nonlinear (elliptic) differential equations.