@article{MAN_1979__246_163332,
     author = {Daniel Flath},
     title = {Atkin-Lehner {Operators.}},
     journal = {Mathematische Annalen},
     pages = {121--124},
     publisher = {mathdoc},
     volume = {246},
     year = {1979},
     zbl = {0405.10020},
     url = {http://geodesic.mathdoc.fr/item/MAN_1979__246_163332/}
}