A critical and effective way to play against the Leningrad is to play e4.....
One of the most direct ways is:
1.d4 f5 2.g3 Nf6 3.Bg2 g6 4.Nd2 4.Nc3
may be answered by d5...(although I would probably prefer Bg7 as in my main variation...)
4-,Bg7 5.e4!? See Diagram.
http://www.france-echecs.com/diagramme/imgboard.phpfen=rnbqk2r/ppppp1bp/5np1/5p2... Kindermann gives (in the english edition of his book):
5.-,fxe4 6.Nxe4 Nxe4 7.Bxe4 d5 8.Bg2 Nc6
9.Ne2 Bg4 10.c3 d5(!, Kindermann)
black gambiting his d5 pawn.
One of the games (Agdestein, Santo Roman)mentioned, actually came from the move order
9.c3 e5 10.dxe5 Nxe5 I'm not really comfortable with giving this d5-pawn away...
White could easily end a pawn up (or go down in fire...

)
What is black's most accurate plan against
10.Bxd5 & Qxd5?(Agdestein move order)
Is there some alternative less risky plan available for black?
Does any other books cover 5.e4!?
(I also have Pedersen's book, but it doesnt...)
Thanks