I'm looking for a text book which has detailed explanations on the subject. If you know it, please let me know. Since I don't have an easy access to a university library, I prefer a book which can be bought(and not so expensive) in an online bookstore like Amazon. Of course, free downloadable books are welcome! Thanks.

**EDIT**
I'm particularly interested in the theory of harmonic integrals on non-compact complete Kähler manifolds.