'Frequency Transformations' (Electromagnetic Waves, 2001), 'Filtering in the Time and Frequency Domains', Chap. 4, pp. 153-211, DOI: 10.1049/SBEW008E_ch4 IET Digital Library, https://digital-library.theiet.org/;jsessionid=vhs9h3hvnxe6.x-iet-live-01content/books/10.1049/sbew008e_ch4