Publikationen in Zusammenarbeit mit Forschern von Universidade de Lisboa (3)

2007

  1. Positivity and lower and upper solutions for fourth order boundary value problems

    Nonlinear Analysis, Theory, Methods and Applications, Vol. 67, Núm. 5, pp. 1599-1612

1996

  1. A positive operator approach to the Neumann problem for a second order ordinary differential equation

    Journal of Mathematical Analysis and Applications, Vol. 204, Núm. 3, pp. 774-785