^James Leo Garrett, Systematic Theology, Volume 2, Second Edition, Wipf and Stock Publishers, USA, 2014, p. 395; "those branches which derived from Baptist or Reformed roots have taught positional and progressive sanctification as distinguishable from baptism in or with the Spirit (e.g., Assemblies of God, International Church of the Foursquare Gospel)."
Blumhofer, Edith L. "Assemblies of God." In The Encyclopedia of Christianity, edited by Erwin Fahlbusch and Geoffrey William Bromiley, 143–146. Vol. 1. Grand Rapids: Wm. B. Eerdmans, 1999. ISBN0802824137
Blumhofer, Edith L. Restoring the Faith: The Assemblies of God, Pentecostalism, and American Culture. (1993). 281 pp. A major scholarly study.
Crowe, Terrence Robert. Pentecostal Unity: Recurring Frustration and Enduring Hopes. (1993). 282 pp.
Fisher, Lyndel Eugene, “The Theological Antecedents of the Assemblies of God: Baptist and Presbyterian Roots” (PhD dissertation, University of Memphis, 2011). DA3476380.
McGee, Gary B. This Gospel . . . Shall Be Preached': A History and Theology of Assemblies of God Foreign Missions since 1959. Springfield, Mo.: Gospel, 1990. 358 pp.
Poloma, Margaret M. The Assemblies of God at the Crossroads: Charisma and Institutional Dilemmas. (1989). 309 pp. scholarly study
Poloma, Margaret M., and John C. Green. The Assemblies of God: Godly Love and the Revitalization of American Pentecostalism (New York University Press; 2010) A sociological study that draws on surveys and interviews conducted in 22 diverse congregations.
Flower Pentecostal Heritage Center (Assemblies of God archives - one of the largest collections of materials documenting the global Pentecostal movement)