@article{MM2_1983__42_154926,
     author = {Vlastimil Ptak},
     title = {Uniqueness in the first maximum problem.},
     journal = {Manuscripta mathematica},
     pages = {101--104},
     publisher = {mathdoc},
     volume = {42},
     year = {1983},
     zbl = {0516.47004},
     url = {http://geodesic.mathdoc.fr/item/MM2_1983__42_154926/}
}