@article{FORUM_1989__1_3_141605,
     author = {T. Kobayashi and T. Sunada and K. Ono},
     title = {Periodic {Schr\"odinger} {Operators} on a {Manifold.}},
     journal = {Forum mathematicum},
     pages = {69--80},
     publisher = {mathdoc},
     volume = {1},
     number = {3},
     year = {1989},
     zbl = {0655.58033},
     url = {http://geodesic.mathdoc.fr/item/FORUM_1989__1_3_141605/}
}