@article{PIM_1990_N_S_48_62_a5,
     author = {J. L. Geluk},
     title = {On {Slowly} {Varying} {Solutions} {Of} {The} {Linear} {Second} {Order} {Differential} {Equation}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {52 },
     publisher = {mathdoc},
     volume = {_N_S_48},
     number = {62},
     year = {1990},
     url = {http://geodesic.mathdoc.fr/item/PIM_1990_N_S_48_62_a5/}
}