If your spiritual father has given you permission to read it and you are looking for it, I recently found the 1st 4 books of it have again become available at Amazon, Glorious Ascension Monastery (formerly ROCOR-L but now JP) and at Light-n-Life (or as some people call it Dark-n-Death) for under $20 a volume! Amazon even offers free shipping if you buy 2 or more volumes!