Unusual Caro-Kann Variation I'm looking for information about the unusual Caro-Kann variation that appears to be a sort of Pirc. I recently ran across this line and I'm struggling to understand why you would deviate from 2... d5.

[FEN ""]

1. e4 c6
2. d4 d6


I can't seem to locate any information on this unusual line. Book suggestions would be helpful.
Its likely a transposition to the Pribyl defense.  1. e4 d6 2. d4 nf6 3. nc3 c6 where black plays e5 at some point.

Its covered in a few books about 1 .. d6 lines where black does not play g6. Also it can transpose to the Old-Indian defense when white plays c4.