@article{AUPO_1971__11_1_a0,
     author = {H\'a\v{c}ik, Milo\v{s}},
     title = {Generalization of amplitude phase and accompanying differential equation},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {7--17},
     publisher = {mathdoc},
     volume = {11},
     number = {1},
     year = {1971},
     mrnumber = {0352583},
     zbl = {0261.34006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_1971__11_1_a0/}
}