APA
Janssen M. A., . (2003). Sunk Cost Effects and Vulnerability to Collapse in Ancient Societies. Chicago-US: Department of Human Sciences.
Chicago
Janssen Marco A, . 2003. Sunk Cost Effects and Vulnerability to Collapse in Ancient Societies. Chicago-US: Department of Human Sciences.
Harvard
Janssen M. A., . (2003). Sunk Cost Effects and Vulnerability to Collapse in Ancient Societies. Chicago-US: Department of Human Sciences.
MLA
Janssen Marco A, . Sunk Cost Effects and Vulnerability to Collapse in Ancient Societies. Chicago-US: Department of Human Sciences. 2003.