I find rereading the original Small Wars Manual and the new draft Marine Corps version to be instructive as well.

Shooter, by Jack Coughlin and others, while not strictly Small Wars does offer some new ways of looking at sniper employment that may prove useful or thought provoking. In a more historical vein, Taking Haiti is interesting but in some places overblown. Actually, I'm working my way through a great deal of stuff on the US involvement in Central America. Mars Learning is perhaps the best look at how the Marine Corps developed its small wars doctrine. Well worth a read (or two).