@article{AM2_1977__16_136694,
     author = {L.L. Keener and W.H. Ling},
     title = {Approximation under an arc length constraint. {(Short} {Communiaction).}},
     journal = {Aequationes mathematicae},
     pages = {194--194},
     publisher = {mathdoc},
     volume = {16},
     year = {1977},
     zbl = {0379.41017},
     url = {http://geodesic.mathdoc.fr/item/AM2_1977__16_136694/}
}