%0 Journal Article %A Timo Ravaska %T Frenet theory of surfaces %J Annales Fennici Mathematici %D 1979 %P 151-168 %V 4 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.5186/aasfm.1978-79.0421/ %R 10.5186/aasfm.1978-79.0421 %G en %F AFM_1979_4_1_a13