Lehnhoff, Sebastian; Uslar, Mathias: 'Smart grid architecture - key elements and definitions' (Energy Engineering, 2017), 'Communication, Control and Security Challenges for the Smart Grid', Chap. 2, pp. 15-43, DOI: 10.1049/PBPO095E_ch2 IET Digital Library, https://digital-library.theiet.org/;jsessionid=2dlkotdqgb58n.x-iet-live-01content/books/10.1049/pbpo095e_ch2