(1)
Total factor productivity and the Environmental Kuznets Curve: A comment and some intuition
Ecological Economics
Volume 63, Issue 1, 15 June 2007, Pages 54-58
URL:[url]http://dx.doi.org/10.1016/j.ecolecon.2006.09.020[/url]
(2)Assessing the Precision of Turning Point Estimates in Polynomial Regression Functions
Authors: Florenz Plassmanna; Neha Khannab
URL
http://www.informaworld.com/smpp/content~db=all~content=a781708631