@article{articleda3d2a81,
title   = {On the validity of the use of a localized approximation for helical beams: I. Formal aspects},
author = {Gouesbet, Gérard and Ambrosio, Leonardo André},
year = {2018},
doi = {10.1016/j.jqsrt.2018.01.001},
journal   = {Journal of Quantitative Spectroscopy & Radiative Transfer}
}