V. M. Babich, D. B. Dement'ev, B. A. Samokish, V. P. Smyshlyaev, “Scattering of a High-Frequency Wave by the Vertex of an Arbitrary Cone (Singular Directions)”, Journal of Mathematical Sciences, 111, № 4, 2002, 3623
Iraklis Sarigiannidis, Massimiliano Casaletti, Matteo Albani, 2025 IEEE International Symposium on Antennas and Propagation and North American Radio Science Meeting (AP-S/CNC-USNC-URSI), 2025, 2809