@incollection{AST_1992__210__65_0, author = {Br\"uning, Jochen and Sunada, Toshikazu}, title = {On the spectrum of gauge-periodic elliptic operators}, booktitle = {M\'ethodes semi-classiques Volume 2 - Colloque international (Nantes, juin 1991)}, series = {Ast\'erisque}, pages = {65--74}, publisher = {Soci\'et\'e math\'ematique de France}, number = {210}, year = {1992}, language = {en}, url = {http://archive.numdam.org/item/AST_1992__210__65_0/} }