Olson, Mancur (1993). „Dictatorship, Democracy, and Development”. American Political Science Review. September 1993 (3): 567—576. JSTOR2938736. doi:10.2307/2938736.
Owens, Emily Greene (2011). „Are Underground Markets Really More Violent? Evidence from Early 20th Century America”. American Law and Economics Review. v13, N1: 1—44. doi:10.1093/aler/ahq017.
Olson, Mancur (1993). „Dictatorship, Democracy, and Development”. American Political Science Review. September 1993 (3): 567—576. JSTOR2938736. doi:10.2307/2938736.