text: http://www.ers.usda.gov/publications/sb968/sb968a.pdf\nhttp://www.atozteacherstuff.com/pages/4454.shtml\nhttp://www.dpi.vic.gov.au/dpi/nreninf.nsf/LinkView/139AA72A06A859ACCA256C7800812F779B49B51BA195265B4A256DEA0027DACB\n\nhope this helps plz give me 10 pts