Geo Widengren
Widengren wrote a series of works on Iranian religions ( in particular Manicheism and Zoroastrism ) , Islam , Judaism , Gnosticism , etc . 
<triplet> Iranian religions <subj> Manicheism <obj> has part <subj> Zoroastrism <obj> has part <triplet> Zoroastrism <subj> Iranian religions <obj> part of