@article{AUPO_1992__31_1_a8,
     author = {Laitoch, Miroslav},
     title = {On functional equation $\varphi\varphi(x)=x$, $x\in(-\infty,\infty)$},
     journal = {Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica},
     pages = {83--100},
     publisher = {mathdoc},
     volume = {31},
     number = {1},
     year = {1992},
     mrnumber = {1212608},
     zbl = {0767.39003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUPO_1992__31_1_a8/}
}