@article{PIM_1984_N_S_36_50_a7,
     author = {M. Elia and M. T. Galizia Angeli},
     title = {The {Length} of a {Lemniscate}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {51 },
     publisher = {mathdoc},
     volume = {_N_S_36},
     number = {50},
     year = {1984},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PIM_1984_N_S_36_50_a7/}
}