Original: Matthew Steel , ( 2005 ) , Pentecostalism in Zambia : Power , Authority and the Overcomers , MSc Dissertation - an examination of the growth and effects of Pentecostalism on development , University of Wales Grant Wacker , ( 2001 ) , Heaven Below : Early Pentecostals and American Culture , Harvard University Press , Cambridge , MA - An academic history of early Pentecostalism .
Simplified: Grant Wacker , ( 2001 ) , Heaven Below : Early Pentecostals and American Culture , Harvard University Press , Cambridge , MA - An academic history of early Pentecostalism .