. "John Mark Purdey (25 December 1953 \u2013 12 November 2006) was an English organic farmer who came to public attention in the 1980s, when he began to circulate his own theories regarding the causes of bovine spongiform encephalopathy (BSE or \"mad cow disease\")."@en . . . . . . . . . . . . . . . . . . . . . "Mark Purdey"@en . "12195660"^^ . . . . . . . . . . . . . . . . . . . . . . . "John Mark Purdey (25 December 1953 \u2013 12 November 2006) was an English organic farmer who came to public attention in the 1980s, when he began to circulate his own theories regarding the causes of bovine spongiform encephalopathy (BSE or \"mad cow disease\")."@en . . . . . . . . . . . . . . . . . . . . . . . . "1118575787"^^ . . . . . . . . . . . . . . . . . . . . "21633"^^ . . .