Não informado. AAPA advisory. American Association of Port Authorities.
Chicago-referens (17:e uppl.)Não informado. AAPA Advisory. Washington: American Association of Port Authorities.
MLA-referens (8:e uppl.)Não informado. AAPA Advisory. American Association of Port Authorities.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.