U.S. Environmental Protection Agency. Profile of the rubber and plastics industry.
Chicago-referens (17:e uppl.)U.S. Environmental Protection Agency. Profile of the Rubber and Plastics Industry.
MLA-referens (9:e uppl.)U.S. Environmental Protection Agency. Profile of the Rubber and Plastics Industry.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.