Even Gallagher in his starting out book, makes mention of the c3/g3 line. He is even going as far as saying that black should not play this line since it is not uncommon knowledge for white players.
So if you wanna try playing it it is at your own risk and you should preferably play it against me

Yes the 6.)c3 line is covered with some depth. Black is given several choices which are as follows 6.)....Bf5 which is the move ussually seen but again several other ideas exist such as 6.)...... Nf3 has some promise for black according  to the book. They also make mention of 6.)...Qd5 . Very interesting book I must say....while I'M sure against best play this variation may suffer but against a lesser or unawares opponent this may proove to be quite a surprise weapon!

I was browsing through the used bookstore today & came across a mint copy of IM Silman's The Dynamic Caro Cann. It would seem the BronsteinLarsen lines & some original Caro lines are the focus of the book. I picked up a copy and though it is ancient (1989) I'M just curious  about how relevant are these lines today? ANyone familiar with the book? How does it hold up??