G. R. S. Mead 
Gnostic John the Baptizer: Selections from the Mandaean John-Book [EPUB ebook] 

This is the extended and annotated edition including
* an extensive annotation of almost 10.000 words about the history and basics of Gnosticism, written by Wilhelm Bousset
The main materials contained in these pages will certainly be new for the vast majority of readers. Moreover the Mandaean narratives, legends and discourses are not only interesting because of their own distinctive matter and manner, but they are also arresting; for they raise a number of problems, some of which are far-reaching and one is fraught with implications of immense importance. The definite solutions of these problems, however, lie in the future, and the most important of them will perhaps never be reached; for, in the absence of straightforward historical information, general agreement on any subject that concerns Christian origins immediately or even indirectly is now well-nigh a psychological impossibility.