These are references for the controversy over Genetically Modified Organisms (GMOs)
Cancer of Corruption, Seeds of Destruction: The Monsanto GMO Whitewash
By F. William Engdahl
Link
Long term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maiz
By Séralini et. al.
Link
The Seralini web site is highly recommended
Link