Piltyay, S. I. “Radiation of the Thin-Walled Circular Waveguide Aperture at Co- and Crosspolarization”. Visnyk NTUU KPI Seriia - Radiotekhnika Radioaparatobuduvannia, no. 39, Oct. 2009, pp. 70-76, doi:10.20535/RADAP.2009.39.70-76.