Section 4.3 of Ciufolini and Wheeler's text "Gravitation and Inertia" is devoted to the origin of inertia. In particular there is a very nice table on pages 250 and 251 that compares classical mechanics, Einstein's Geometrodynamics (General Relativity in Wheelerese), and Einstein's Geometrodynamics with additional requirements. You may find this section of the book interesting. (Actually, the whole book is interesting). Also there is a book of essays: "Gravitation and Relativity" edited by H.Y. Chiu and W.F. Hoffman that has two relevant chapters: Chapter 6, "Mach's Princile and Experiments on Mass Anisotropy" by V.W. Hughes and Chapter 7 "The Many Faces of Mach" by R.H. Dicke.
