A result concerning the existence of positive solutions for the Dirichlet boundary value problem-(φp (u'))' = f (t, u), t ∆ (0, 1), u(0) = c > 0 and u (1) = 0, is given in this paper. Here f (t, y) may change sign and may be singular at y = 0.
"EXISTENCE OF POSITIVE SOLUTIONS FOR THE ONE-DIMENSION SINGULAR P-LAPLACIAN EQUATION WITH SIGN CHANGING NONLINEARITIES VIA THE METHOD OF UPPER AND LOWER SOLUTION." Methods Appl. Anal. 10 (4) 533 - 542, Dec 2003.