1. A detailed summary of the status of this field of physics up to 1978, including an exhaustive list of historical references, can be found in the review article Electrical Conductivity in Inhomogeneous Media by R. Landauer, in “Electrical Transport and Optical Properties of Inhomogeneous Media,” Eds. J. C. Garland and D. B. Tanner, AIP Conf. Proc. No. 40, pp. 2–45, 1978
2. A detailed discussion of these definitions and the various approximations that have been developed to calculate εe can be found in a series of published lecture notes prepared by one of the authors: Bulk Physical Properties of Composite Media by D. J. Bergman, in “Les Méthodes de l'Homogénéisation: Théorie et Applications en Physique,” École d'Été d'Analyse Numérique, pp. 1–128, Edition Eyrolles, Paris, 1985
3. Solid Mixture Permittivities
4. The dielectric constant of a composite material—A problem in classical physics
5. “Willis E. Lamb a Festschrift on the Occasion of his 75th Birthday”,1978