Gaya APA

Johnston, D., Zimmermann, R. (2002). Unjustified Enrichment: Key Issues in Comparative Perspective (1). United Kingdom: Cambridge University Press.

Gaya MLA

Johnston, David., Zimmermann, Reinhard. "Unjustified Enrichment: Key Issues in Comparative Perspective". 1 United Kingdom: Cambridge University Press, 2002. Text.