APA (7th ed.) Zitazioa
HAYDEN, C. (1989). ELDER CAMPERS HELPING OTHERS - THE ECHO PROJECT: A UNIQUE INTERGENERATIONAL MODEL.
Chicago Style (17th ed.) Zitazioa
HAYDEN, C.S. ELDER CAMPERS HELPING OTHERS - THE ECHO PROJECT: A UNIQUE INTERGENERATIONAL MODEL. 1989.
MLA (9th ed.) Zitazioa
HAYDEN, C.S. ELDER CAMPERS HELPING OTHERS - THE ECHO PROJECT: A UNIQUE INTERGENERATIONAL MODEL. 1989.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.