Hill, M., & Frederic Varone. (2021). The Public Policy Progress (8th edition.). Routledge.
Lua i Stíl Chicago (17ú heag.)Hill, Michael, agus Frederic Varone. The Public Policy Progress. 8th edition. New York: Routledge, 2021.
Lua MLA (9ú heag.)Hill, Michael, agus Frederic Varone. The Public Policy Progress. 8th edition. Routledge, 2021.