F. D’Agostino, F. Ferrara, C. Gennarelli, R. Guerriero, and M. Migliozzi. “A Planar NF–FF Transformation for Quasi-Spherical Antennas Using the Innovative Spiral Scanning”. Applied Computational Electromagnetics Society Journal (ACES), vol. 33, no. 01, July 2021, pp. 115-8, https://journals.riverpublishers.com/index.php/ACES/article/view/9367.