American Bee Journal Article – “An Estimate of Managed Colony Losses in the Winter of 2006 – 2007: A Report Commissioned by the Apiary Inspectors of America by Dennis vanEngelsdorp, Robyn Underwood, Dewey Caron, Jerry Hayes, Jr. http://maarec.psu.edu/CCDPpt/CCDJuly07ABJArticle-1.pdf