Campaign books.....for DS2

Picked up "Operation Distant Fire" for Renegade Legion (thanks to the
lister
whom recommended it)--great sourcebook for campaigning,as well as the
Centurion Tech Update,2nd ACR,and Harbingers of Death.

My question is what other books are out there like these? Specifically
ones
that could be used for DS2.....

Thanks.....