@article{PORMA_2004__61_3_51278,
     author = {Furta, Stanislav and Zampieri, Gaetano},
     title = {Cruising in a central force field.},
     journal = {Portugaliae mathematica},
     pages = {259--280},
     publisher = {mathdoc},
     volume = {61},
     number = {3},
     year = {2004},
     zbl = {1062.37061},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_2004__61_3_51278/}
}