@article{MS2_1984__54_166895, author = {Arne Jensen}, title = {On {Lavine's} formula for time-delay.}, journal = {Mathematica Scandinavica}, pages = {253--261}, publisher = {mathdoc}, volume = {54}, year = {1984}, zbl = {0529.46006}, url = {http://geodesic.mathdoc.fr/item/MS2_1984__54_166895/} }