Kelen, A. (2001). The gratis economy: Privately provided public goods. CEU Press.
Chicago Style (17th ed.) CitationKelen, András. The Gratis Economy: Privately Provided Public Goods. Budapest: CEU Press, 2001.
MLA (9th ed.) CitationKelen, András. The Gratis Economy: Privately Provided Public Goods. CEU Press, 2001.
Warning: These citations may not always be 100% accurate.