Question on Omaha/8 books (mainly limit play)

[MediaPA]

I'm looking to learn this game well. I find it to be the most enjoyable of the 'window' games. I did a search and found the following books for high/low. Anyone have any suggestions as to what two (I guess) would probably help the most (or reasons not to get certain books).

Thanks.

Winning Omaha/8 Poker by Mark Tenner, Lou Krieger
How to Win at Omaha High-Low Poker by Mike Cappelletti
High-Low-Split Poker, Seven-Card Stud and Omaha Eight-or-better for Advan (Advance Player) by Ray Zee
Doyle Brunson's Super System II by Doyle Brunson
Omaha Hi-Lo Poker by Shane Smith
Omaha High-Low: Play To Win With The Odds by Bill Boston