'Large-scale channel effects' (Telecommunications, 2017), 'Introduction to Digital Wireless Communications', Chap. 2, pp. 13-31, DOI: 10.1049/PBTE072E_ch2
IET Digital Library, https://digital-library.theiet.org/;jsessionid=5dchf1wqq3q.x-iet-live-01content/books/10.1049/pbte072e_ch2