Kelen, A. (2001). The gratis economy: Privately provided public goods (English ed.). CEU Press.
Citación estilo ChicagoKelen, András. The Gratis Economy: Privately Provided Public Goods. English ed. Budapest: CEU Press, 2001.
Cita MLAKelen, András. The Gratis Economy: Privately Provided Public Goods. English ed. CEU Press, 2001.
Warning: These citations may not always be 100% accurate.