Cabello, A. e Hajto, Z. 1995. Stratifications Adapted to Finite Families of Difierentíal 1-Forms (Pfafilan Geometry-PartOne). Revista Matemática Complutense. 8, 2 (jan. 1995), 269. DOI:https://doi.org/10.5209/rev_REMA.1995.v8.n2.17643.