Παραπομπή APA

Harcourt,G C, & Karmel,P H. (1968). Economic activity. Cambridge University Press.

Παραπομπή Chicago Style

Harcourt,G C, και Karmel,P H. Economic Activity. Cambridge: Cambridge University Press, 1968.

Παραπομπή MLA

Harcourt,G C, και Karmel,P H. Economic Activity. Cambridge University Press, 1968.