APA aipamena

(2012). Green Source March s/d June th. 2012. The McGraw-Hill.

Chicago Style aipamena

Green Source March S/d June Th. 2012. The McGraw-Hill, 2012.

MLA aipamena

Green Source March S/d June Th. 2012. The McGraw-Hill, 2012.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.