⁹Many good books review these empirical models, for instance in [3] ch. 2, [1] ch. 4, [6], [19] ch. 6-7. But too many others contain typos and mistakes: for instance Fixed Broadband Wireless System Design (H.R. Anderson – Wiley, Chichester, 2003) presents a good orderly review of several propagation models, including the §3.4.1 IEEE 802.16 (SUI) model – unfortunately it contains two typos in §3.4.1 equations (3.18) and (3.20), which make the book impossible to recommend as a reference on this subject.

Referring to the original work is sometimes worth it, especially in the case of [32] where important key learnings and analyses are almost as important as the model itself.