Motion Mountain The Free Physics Textbook  
With little mathematics, the text explores the most fascinating parts of mechanics, thermodynamics, special and general relativity, electrodynamics, quantum theory and modern attempts at unification. Written in English, its over 1200 pages are provided for students, teachers, and for anybody who is interested in the precise description of nature. 
A Heat Transfer Textbook, Third Edition  
This textbook is an introduction to heat and mass transfer oriented toward engineering students. The subjects covered include heat conduction, forced and natural convection, thermal radiation, boiling, condensation, heat exchangers, and mass transfer. 
Introduction to String Field Theory  
Introduction to String Field Theory by Warren Siegel is available in several formats without charge. 
The Electromagnetic Field Theory Textbook  
This book is written mainly from a classical field theoretical point of view, emphasising fundamental and subtle properties of the EM field and includes a comprehensive appendix on the mathematical methods used. 
The Electromagnetic Field Theory Exercises  
A companion book with exercises (electrodynamics problems with solutions) is available for The Electromagnetic Field Theory Textbook. 
