@article{10_4064_ap_44_3_297_308,
     author = {Barbara Alfawicka},
     title = {Inverse problems connected with periods of oscillations described by ẍ + g(x) = 0},
     journal = {Annales Polonici Mathematici},
     pages = {297--308},
     publisher = {mathdoc},
     volume = {44},
     number = {3},
     year = {1984},
     doi = {10.4064/ap-44-3-297-308},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/ap-44-3-297-308/}
}