Exposition of the Doctrine of Karma: Now Available!
This book is a nice analysis of the idea of karma, from a specifically Theosophical perspective. The authors' name is a pseudonym so it isn't entirely clear which theosophist actually compiled the materials here. It's a more legitimate take on the subject than much literature about karma- often it is boiled down to a simplified, singular idea and ideas like national or group karma are deliberately overlooked because they (in truth) don't make sense under the concepts of Western thought.
It manages to avoid the overtly new-age style of some then contemporary manuscripts which devolve into talking about psychic forces and other things which were in vogue at the time, and contains a good bit of religious history, to boot.