'Appendix B. References and further reading' (Transportation, 2018), 'Road Pricing: Technologies, economics and acceptability', Chap. appendixb, pp. 587-588, DOI: 10.1049/PBTR008E_appendixb
IET Digital Library, https://digital-library.theiet.org/;jsessionid=769ish85ju8iq.x-iet-live-01content/books/10.1049/pbtr008e_appendixb