These books were particularly helpful to me in my study, and I hope that you will find the compilation of the digital versions listed below helpful as well. Click the title to go to where they are available digitally.
Vision of the Disinherited by Robert Mapes Anderson
The Woman Evangelist: The Life and Times of Charismatic Evangelist Maria B. Woodworth-Etter by Wayne E. Warner
Restoring the Faith: The Assemblies of God, Pentecostalism, and American Culture by Edith L. Blumhofer
The Assemblies of God: A Chapter in the Story of American Pentecostalism by Edith Waldvogel Blumhofer
People of the Spirit: The Assemblies of God by Gary McGee
Suddenly from Heaven: A History of the Assemblies of God by Carl Brumback
Heaven Below: Early Pentecostals and American Culture by Grant Wacker
The Woman Evangelist: The Life and Times of Charismatic Evangelist Maria B. Woodworth-Etter by Wayne E. Warner
Restoring the Faith: The Assemblies of God, Pentecostalism, and American Culture by Edith L. Blumhofer
The Assemblies of God: A Chapter in the Story of American Pentecostalism by Edith Waldvogel Blumhofer
People of the Spirit: The Assemblies of God by Gary McGee
Suddenly from Heaven: A History of the Assemblies of God by Carl Brumback
Heaven Below: Early Pentecostals and American Culture by Grant Wacker
Below are histories I am currently studying: