L. D. Landau & E. M. Lifshitz 
Course of Theoretical Physics [PDF ebook] 

Course of Theoretical Physics, Volume 5: Statistical Physics, Third Edition, Part 1 covers the fundamental principles of statistical physics and thermodynamic quantities. The book discusses the Gibbs and Maxwellian distributions; the Boltzmann distribution for ideal gases; and the Fermi and Bose distributions. Solids are tackled with regard to their application of statistical methods of calculating the thermodynamic quantities. The book describes the deviations of gases from the ideal state, conditions of phase equilibrium, solutions, and chemical reactions. The text also discusses the properties of matter at very high density; the Gaussian distribution; fluctuations of the fundamental thermodynamic quantities; and fluctuations in solids and ideal gases. The symmetry of crystals; phase transitions of the second kind and critical phenomena; and surfaces are considered as well. Students taking statistical physics and those involved in the areas of statistical physics will find the book invaluable.