Não informado. (2002). Canadian pit and quarry. National Business Publications.
Chicago-referens (17:e uppl.)Não informado. Canadian Pit and Quarry. Gardenvale, Canada: National Business Publications, 2002.
MLA-referens (8:e uppl.)Não informado. Canadian Pit and Quarry. National Business Publications, 2002.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.