https://www.google.de/search?q=Frontier+Knowledge+and+Scientific+Production%3A+Evidence+from+the+Collapse+of+International+Science+in+the+Wake+of+WWI&ie=utf-8&oe=utf-8&client=firefox-b&gfe_rd=cr&ei=qa5FV_uxNtD4-gb3obX4DA
Go to speaker website.