1. DuPont, Evergreen To Recycle Carpet Forever
2. http://www.laep.org/uclasp/issues/landfills/litter.html, cited 5 June 2003.
3. E.F. Moran Jr., U.S. Patent 5,310,905 (1994).
4. R.J. McKinney, U.S. Patent 5,302,756 (1994)
5. A. Lambert, G.H. Lang, GB Patent 1,172,997 (1969)