@article{JLT_2003_13_1_JLT_2003_13_1_a12,
     author = {G. Mari Beffa},
     title = {Relative and {Absolute} {Differential} {Invariants} for {Conformal} {Curves}},
     journal = {Journal of Lie theory},
     pages = {213--245},
     year = {2003},
     volume = {13},
     number = {1},
     url = {http://geodesic.mathdoc.fr/item/JLT_2003_13_1_JLT_2003_13_1_a12/}
}