'Appendix A. Glossary of acronyms and technical terms' (Transportation, 2018), 'Road Pricing: Technologies, economics and acceptability', Chap. appendixa, pp. 571-586, DOI: 10.1049/PBTR008E_appendixa
IET Digital Library, https://digital-library.theiet.org/;jsessionid=17num16xsv9fm.x-iet-live-01content/books/10.1049/pbtr008e_appendixa