@article{GDZPPN002225921,
title = {Periodic Schr\"odinger Operators with (Non-Periodic) Magnetic and Electric Potentials.},
journal = {Manuscripta mathematica},
volume = {46},
year = {1984},
pages = {19-38},
zbl = {0566.35033},
url = {http://dml.mathdoc.fr/item/GDZPPN002225921}
}
Hempel, Rainer. Periodic Schrödinger Operators with (Non-Periodic) Magnetic and Electric Potentials.. Manuscripta mathematica, Tome 46 (1984) pp. 19-38. http://gdmltest.u-ga.fr/item/GDZPPN002225921/