@article{53872e8def53411fafdf617d5223eacd,
title = "Momentum Operators in the Unit Square",
keywords = "boundary values for linear first-order PDE, deficiency indices, Fourier multiplier operator, Fourier series, Fourier transform, momentum operator, selfadjoint extensions, spectral pairs, Spectral sets, square, tilings, Unbounded operators",
author = "Steen Pedersen and Feng Tian",
year = "2013",
month = sep,
doi = "10.1007/s00020-013-2078-9",
language = "English",
volume = "77",
pages = "57--88",
journal = "Integral Equations and Operator Theory",
issn = "0378-620X",
number = "1",
}