http://www.factmonster.com/ipka/A0775891.html

http://www.sunysb.edu/centralservices/recycling/4rs.shtml

http://www.highcountryconservation.org/reduce_reuse_recycle.htm

http://www.dnr.mo.gov/env/swmp/pubs-reports/threers.htm

http://www.cabq.gov/solidwaste/recycling/threers

http://www.healthgoods.com/education/environment_information/Solid_Waste/produce_less_waste.htm

http://www.epa.gov/msw/reduce.htm

http://www.burningman.com/environment/sixrs.html

http://www.fw.vt.edu/dendro/Forsite/2002presentations/thethreers.htm

http://www.genesysdtp.com/waterproof.htm