Wen-bo, Q., Zhong-xin, Z. & Jun-de, W. Appl Math Mech (2002) 23: 854. doi:10.1007/BF02456982
A fixed point theorem is used to study a singular second order three-point boundary value problem. The problem is more general. Combining the method of constructing Green functions with operators defined piecewise, the existence resultof positive solutions to a singular second order three-point boundary value problem is established. The nonlinearity can be allowed to change sign.