@article{PIM_1972_N_S_14_28_a20,
     author = {Veljko Vuji\v{c}i\'c},
     title = {Some {First} {Integrals} {Of} {Differential} {Equations} {Of} {Motion} {Of} {A} {Mechanical} {System}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {157 },
     publisher = {mathdoc},
     volume = {_N_S_14},
     number = {28},
     year = {1972},
     url = {http://geodesic.mathdoc.fr/item/PIM_1972_N_S_14_28_a20/}
}