Qiang Duan, : 'Network-as-a-Service in software-defined networking for end-to-end quality of service provisioning' (Telecommunications, 2017), 'Network as a Service for Next Generation Internet', Chap. 11, pp. 265-286, DOI: 10.1049/PBTE073E_ch11
IET Digital Library, https://digital-library.theiet.org/;jsessionid=7f29tfh2b0hhl.x-iet-live-01content/books/10.1049/pbte073e_ch11