Meran semi slav with 7.g4

1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. e3 e6 5. Nf3 Nbd7 6. Qc2 Bd6 7. g4 *

was wondering if anyone knows any good book recommending this line or where shall i look to find some theory abt this variation?

There's decent coverage in Chess Explained: The Meran Semi-Slav

Like Metaknight said, Shabalov is a world-renowned expert on this line. Kasparov - Deep Junior is also a highly instructive game about this line. It is EXTREMELY dangerous for black. Black must know his stuff or he will get into trouble.

This is not a Meran. The Meran occurs after 6.Bd3 dxc4

@Expertise87, the book mentioned by ArthurMachen, Chess Explained: The Meran SemiSlav by Vera covers everything after 5 e3.  That includes the Shirov-Shabalov/Latvian Gambit.  I also recommend the book.