Ida, Nathan: 'Appendix B: True north calculations' (Telecommunications, 2017), 'Transceiver and System Design for Digital Communications, 5th Edition', Chap. appendixb, pp. 487-487, DOI: 10.1049/PBTE080E_appendixb
IET Digital Library, https://digital-library.theiet.org/;jsessionid=2iv7d65h40qn7.x-iet-live-01content/books/10.1049/pbte080e_appendixb