%0 Journal Article %A Chao, Dao Qui %A Krupka, Demeter %T 3rd order differential invariants of coframes %J Mathematica slovaca %D 1999 %P 563-576 %V 49 %N 5 %I mathdoc %U http://geodesic.mathdoc.fr/item/MASLO_1999__49_5_a3/ %G en %F MASLO_1999__49_5_a3