TY - JOUR AU - Coll, B. AU - Gasull, A. AU - Prohens, R. TI - Differential Equations Defined by the Sum of two Quasi-Homogeneous Vector Fields JO - Canadian journal of mathematics PY - 1997 SP - 212 EP - 231 VL - 49 IS - 2 UR - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1997-011-0/ DO - 10.4153/CJM-1997-011-0 ID - 10_4153_CJM_1997_011_0 ER -