1. 1. M. Arias, J. Campos, M. Cuesta and J-P. Gossez, Asymmetric elliptic problems with indefinite weights, Ann. Inst. H. Poincare, An. non li., 19, 581-616, (2002).
2. 2. M. Arias, J. Campos, M. Cuesta and J-P. Gossez, An asymmetric Neumann problem with weights, Ann. Inst. H. Poincare, An. non li., 25 (2), 267-280, (2002).
3. 3. A. Anane, O. Chakrone, B. Karim and A. Zerouali, An Asymmetric Steklov Problem with weights: the singular case, Bol. Soc. Parananense de Mat. (3s.) v. 27: 2, 35-41, (2009).
4. Nonresonnance between the first two eigenvalues for a Steklov problem
5. 5. A. Anane, O. Chakrone, B. Karim and A. Zerouali, A non resonance under and between the two first eigenvalues in a nonlinear boundary problem, Bol. Soc. Parananense de Mat. (3s.) v. 28: 2, 57-71, (2010).