On the hypoellipticity of degenerate elliptic boundary value problemsBERGAMASCO, A. P; PETRONILHO, G.Journal of mathematical analysis and applications. 1992, Vol 171, Num 2, pp 407-417, issn 0022-247XArticle

Re-establishment of uniqueness. IIBERGAMASCO, A. P; PETRONILHO, G.Journal of differential equations (Print). 1994, Vol 110, Num 1, pp 134-142, issn 0022-0396Article

Solvability in the large for a class of vector fields on the torusBERGAMASCO, A. P; DATTORI DA SILVA, P. L.Journal de mathématiques pures et appliquées. 2006, Vol 86, Num 5, pp 427-447, issn 0021-7824, 21 p.Article

Uniqueness in a doubly characteristic Cauchy problemBERGAMASCO, A. P; DE SOUZA RIBEIRO, H.Pacific journal of mathematics. 1989, Vol 136, Num 2, pp 229-240, issn 0030-8730Article

On the regularity up to the boundary in the Dirichlet problem for degenerate elliptic equationsBERGAMASCO, A. P; GERSZONOWICZ, J. A; PETRONILHO, G et al.Transactions of the American Mathematical Society. 1989, Vol 313, Num 1, pp 317-329, issn 0002-9947Article