Immigration policy and the terrorist threat in Canada and the United States. FraserInstitute. : 96 [2012-07-22]. ISBN 978-0-88975-235-1. (原始内容存档于2020-08-18). Urban-rural
Publishers), 1999, 100 (3-4): 203–223 Economic Freedom of the World 2005, FraserInstitute De Haan, J. and C. L. J. Siermann (1998). Further Evidence on the Relationship