Cita APA (7a ed.)

Kelen, A. (2002). The Gratis Economy: Privately Provided Public Goods. Central European University Press.

Cita Chicago Style (17a ed.)

Kelen, András. The Gratis Economy: Privately Provided Public Goods. New York: Central European University Press, 2002.

Cita MLA (8a ed.)

Kelen, András. The Gratis Economy: Privately Provided Public Goods. Central European University Press, 2002.