@article {1711.03950, archivePrefix = {arXiv}, eprint = {1711.03950}, primaryClass = {math-ph}, author = {Leonid Parnovski and Roman Shterenberg}, title = {Perturbation theory for almost-periodic potentials I. One-dimensional case}, year = {2017}, url = {http://arxiv.org/abs/1711.03950} }