@article{MZ_1950__52_169113,
     author = {H. Schmidt},
     title = {Zur {Approximation} und {Kettenbruchentwicklung} quadratischer {Zahlen}},
     journal = {Mathematische Zeitschrift},
     pages = {168--192},
     year = {1950},
     volume = {52},
     zbl = {0033.16701},
     url = {http://geodesic.mathdoc.fr/item/MZ_1950__52_169113/}
}