Numerous books written about the Mandaeans by eminent professors and experts should be read and added to your library. 

Due to its status as the last Gnostic religion and the fact that many aspects of its history are still controversial or undocumented very well, the Mandaean and Mandaeism have received significant attention from theologians at several institutions in recent years.

It will be quite difficult to trust the veracity of such study or literature if you don’t speak or comprehend Mandaean and Aramaic. Missing significant portions of the translation is inexcusable for a religion as important as the last Gnostic one.