Popović, B. D.; Kolundźija, B. M: 'Analysis of Metallic Antennas and Scatterers' (Electromagnetic Waves, 1994) DOI: 
IET Digital Library, https://digital-library.theiet.org/;jsessionid=12bgok0w67yc0.x-iet-live-01content/books/ew/pbew038e