Most classical text is Gregg&Sing. In Chapter 2 you have 60 pages dedicated to study BET surface area of non-porous solids. Also, there are two newer editions by Rouquerol. References for the three books are below. Each is an excellent starting point.
Gregg, S. J., and Kenneth SW Sing. "Adsorption, Surface Area, and Porosity." (1983).
Adsorption by Powders and Porous Solids
Principles, Methodology and Applications
About this Book
Author(s):
Françoise Rouquerol, Jean Rouquerol and Kenneth Sing
ISBN: 978-0-12-598920-6
cover Adsorption by Powders and Porous Solids (Second Edition)
Principles, Methodology and Applications
About this Book
Author(s):
Jean Rouquerol, Françoise Rouquerol, Philip Llewellyn, Guillaume Maurin and Kenneth S.W. Sing