APA aipamena

(1993). General Catalogue. Ley bold Didactic GMBH.

Chicago Style aipamena

General Catalogue. Ley bold Didactic GMBH, 1993.

MLA aipamena

General Catalogue. Ley bold Didactic GMBH, 1993.

Kontuz: berrikusi erreferentzia hauek erabili aurretik.