%0 Journal Article %A Jorge Luiz Deolindo-Silva %T On the characteristic curves on a surface in R^4 %J Journal of Singularities %D 2020 %P 28-39 %V 22 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.5427/jsing.2020.22c/ %R 10.5427/jsing.2020.22c %F 10_5427_jsing_2020_22c