“…This quantum model has been approached also with some completely different techniques like asymptotic methods for largely separated AB solenoids, semiclassical analysis and a complex scaling method [11,28,3,4]. One may also mention more complex models comprising, apart of AB magnetic fluxes, also additional potentials or magnetic fields [16,19], or models with an arbitrary finite number of AB solenoids or even with countably many solenoids arranged in a lattice [26,17,18]. On the other hand, the method stemming from the original ideas of Schulman and Sunada turned out to be fruitful also in analysis of other interesting models like Brownian random walk on the twice punctured plane [10,7].…”