SOG MAC V Studies and Observation Group (Behind - Enemy - Lines) 4 Volume Collectors Set, by Harve Saal.  All books are unopened and still in the original shrink wrap.  These books are VERY RARE and collectible.  The 4 Volume Collection includes Volume 1 - Historical Evolution,  Volume 2 - Locations, Volume 3 - Legends, Volume 4- Appendixes.  This collection is a great history of the men and the mission's of MAC V SOG that took place during the Vietnam War. These books where printed in 1990 and only 1000 sets where ever printed.