1. Rubbish!: The Archaeology of Garbage;Murphy,2001
2. http://www.cfact.org – Committee for a Constructive Tomorrow.
3. http://www.bos.frb.org/economic/nerr/rr2002/q1/waste.htm – Federal Reserve Bank of Boston.
4. http://www.time.com/time/magazine/article/0,9171,964245,00.html – Time.