This page, linked at the bottom of the article, has a table each line of which links to a page with references: http://www.drawdown.org/solutions-summary-by-ran

This page, linked at the bottom of the article, has a table each line of which links to a page with references: http://www.drawdown.org/solutions-summary-by-rank http://www.drawdown.org/solutions-summary-by-rank