It's pretty much a mad dash once the invasion starts to find the spell caster generals (I think they are the only ones that drop the 50 SDI book but could be wrong). It's a crapshoot to find as they spawn randomly so I'll be running around trying to find one and won't come across any until it's maybe 50% HP and it's kinda pointless at that point because I've never gotten a single book once the general/captain is below 50% HP. Heck even when attacked at 75% HP and doing massive damage (Cu + WOD) I still don't always get a book.
I wish they would have made it so that mage generals would still spawn throughout the entire invasion (or at least a chance to spawn) so that when everyone leaves 5-10min into the invasion when all the mages are dead that the people sticking around working it could actually be rewarded.
I wish they would have made it so that mage generals would still spawn throughout the entire invasion (or at least a chance to spawn) so that when everyone leaves 5-10min into the invasion when all the mages are dead that the people sticking around working it could actually be rewarded.