Fagan, M. (1991). Challenge for change: [geographical approaches to selected world issues] (2. ed.). McGraw-Hill.
Citazione stile Chigago Style (17a edizione)Fagan, Margaret. Challenge for Change: [geographical Approaches to Selected World Issues]. 2. ed. Toronto [u.a.]: McGraw-Hill, 1991.
Citatione MLA (9a ed.)Fagan, Margaret. Challenge for Change: [geographical Approaches to Selected World Issues]. 2. ed. McGraw-Hill, 1991.
Attenzione: Queste citazioni potrebbero non essere precise al 100%.