J. T. Conway, Analytical solution for the solid angle subtended at any point by an ellipse via a point source radiation vector potential. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, pp.17-27, 2010.

J. R. Frisvad, Building an Orthonormal Basis from a 3D Unit Vector Without Normalization, Journal of Graphics Tools, vol.4, issue.4, pp.151-159
DOI : 10.1080/2165347X.2012.689606