TY - JOUR AU - A. Eada TI - A two-point boundary value problem for systems of ordinary non-linear differential equations and the lemma of ViĊĦik JO - Commentationes Mathematicae PY - 1980 SP - 157 EP - 161 VL - 21 IS - 1 PB - mathdoc UR - http://geodesic.mathdoc.fr/articles/10.14708/cm.v21i1.5972/ DO - 10.14708/cm.v21i1.5972 LA - pl ID - 10_14708_cm_v21i1_5972 ER -