{{sfn|Trigg|1983|p=}}
* {{cite book | last=Trigg | first=Joseph W. | title=Origen: Includes index | publisher=John Knox Press | publication-place=Atlanta, Ga | date=1983 | isbn=978-0-8042-0945-8}}
<ref name="a657">{{cite book | last=Trigg | first=Joseph W. | title=Origen: Includes index | publisher=John Knox Press | publication-place=Atlanta, Ga | date=1983 | isbn=978-0-8042-0945-8 | page=}}</ref>