Notes, Comments and Preliminary results Jan 20 2012 Tsangyao Chang , Chia-hao Lee and Guochen Pan   Purchasing Power Parity in African Countries: Further Evidence based on the ADL Test for Threshold Cointegration   Abstract  Contact Information  Citation  Full Text  -  Preliminary Result   Apr 17 2011 Tsangyao Chang , Chia-hao Lee and Pei-I Chou   Purchasing power parity in G-7 countries: Further evidence based on ADL test for threshold cointegration   Abstract  Contact Information  Citation  Full Text  -  Preliminary Result