1. arXiv.org:Open access to 925,835 e-prints in Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics
  2. CRC netBase:CRCnetBASE, the award-winning Science, Technology, and Medicine eBook platform from CRC Press, offers a comprehensive eBook collection that delivers more than 12,000 references in over 350 subject areas and more than 40 collections.
  3. College Open Textbooks:open and free textbooks that may be suitable for use in community college courses from the list of Subjects provided. For descriptions of these open textbooks, see listings in MERLOT and OER Commons. Most of the textbooks on this list have Creative Commons (CC) open licenses or GNU-Free Document License. Others are U.S. government documents in the public domain (PD).
  4. Directory Open Access Books:The primary aim of DOAB is to increase discoverability of Open Access books. Academic publishers are invited to provide metadata of their Open Access books to DOAB. Metadata will be harvestable in order to maximize dissemination, visibility and impact.
  5. Freebookcentre:    Freebookcentre.net contains links to thousands of free online technical books. The books collection are either downloadable or can be viewed online. Our collections include core Computer Science, Electronics, Science, Medical and many more. You are welcome to follow the following links for the free books tour
  6. E-Books.Com:Physics books Available is more then several books  6 363 included thier .
  7. E-Books Directory:The site is launched in 2008, it is a database-driven web site using PHP scripting language and MySQL relational database. There are currently 8782 e-books listed in 652 categories.
  8. Free Science Of Physics:FreeScience.info is an initiative to substitute real libraries witha virtual one, where it will be possible download all books, in a printable format, mainly PDF.
  9. INTECH Open Access Publishers:InTech is a pioneer and world's largest multidisciplinary open access publisher of books covering the fields of Science, Technology and Medicine. Since 2004, InTech has collaborated with more than 86349 authors and published 2362 books and 6 journals with the aim of providing free online access to high-quality research and helping leading academics to make their work visible and accessible to diverse new audiences around the world.
  10. IOP Science:IOP ebooks™ is a brand new book programme that brings together innovative digital publishing with leading voices from across physics to create the essential collection of physics books for a digital world. Created through collaboration with leading researchers in their field, IOP ebooks™ feature must-read content for the physics community
  11. IT-Ebooks.info:Access eBooks - IT eBook free ... Open Source Identity Management Patterns ... and quickly teach yourself how to build your own database with Access 2013.
  12. NASA Aeronautic E Books:Many of the biggest achievements in aeronautics research are chronicled in books rich with detail, personal stories, surprising twists of fate and revolutionary discoveries that have influenced the experience of flight for millions of people
  14. Open Ebooks Library:Subjects covered in these ebooks are esoteric theory, formula and physical constants, physical phenomena of universe, space, time and gravitation, relativity theory, aether and gravitation, eninstein theory of relativity, quaternions in physics, electricity, theories of great physical forces, etc and more
  15. OECDLibrary:OECD iLibrary is the online library of the Organisation for Economic Cooperation and Development (OECD) featuring its books,  papers and statistics and is the gateway to OECD’s analysis and data.OECD iLibrary presents all content so users can find - and cite - tables and databases as easily as articles or chapters in any available format: PDF, WEB, XLS, DATA, ePUB, READ.
  16. Pdfsb online E Books:On this site you can read and download free books online in pdf format. It's database covers an extensive array of pdf books in different languages that describe all types of subjects and topics. For those who're looking for free e books online, this site has made it easier for readers to search for what they want, through their built-in search engine and the additional filters.
  17. Physicsdatabase:Some great new physics books have been released recently, so, as always, here’s a short overview of 5 top physics books that you should definitely check out
  18. Physics Books Online:Science Books Online is a directory of free science texts, e-books, monographs, lecture notes, and other science related documents
  19. University of California eScholarship Repository:eScholarship provides Open-Access scholarly publishing services to  the University of California and delivers a dynamic research platform to scholars worldwide.
  20. Scientific Research: is an academic publisher of open access journals. It also publishes academic books and conference proceedings. SCIRP currently has more than 200 open access journals in the areas of science, technology and medicine.
  21. ScienceDirect.com: is a leading full-text scientific database offering journal articles and book chapters from more than 2,500 journals and almost 20,000 books.
  22. Applied Physics:Research interests are in the theoretical explorations of electronic properties of various types of condensed matter. (Found: 104 777 book)
  23. Atomic Physics:Historical perspective; Spectroscopy; Bohr model; Schrodinger equation of the hydrogen atom; Optical transitions in a two-level system; Magnetic effects in atoms and the electron spin; Many electron atoms; Energy levels in molecules.
  24. Basic Electronics:systems and electric power systems. The emphasis in this chapter is on the basic techniques for the analysis of electronic circuits...(120 937 books)
  25. Crystal Growth And Thin Films:  is an available in many books in crystal growth and thin films the different categories,title,etc.                  (4 088books).....
  26. Electromagnetism:The book takes a logical step-by-step progression through electromagnetic waves in empty space, dispersive media and in waveguides. The book ends with radiation and scattering, initially using an heuristic approach to derive Larmor's formula and applying it to simple problems.
  27. Mathematical Physics: Categories of Field Theory, Geometry & Physics, Quaternions, String Theory
  28. Mechanics:Theory Of Vectors; Kinematics Of A Point; Dynamics Of A Material Point; Geometry Of Masses; Systems Of Material Points; Statics Of A Rigid Body; Kinematics Of A Rigid Body; Dynamics Of A Rigid Body; Principle Of Virtual Work; Dynamics Of Holonomic Systems; Variational Principles Op Mechanics.
  29. Modern Physics:Modern” physics means physics based on the two major breakthroughs of the early the twentieth century: relativity and quantum mechanics.(96 746 books) 
  30. Molecular Physics:Energy levels in molecules -- the quantum structure; Transitions between quantum states; High vibrational levels in the WKB-approximation; Electronic states; Open Shell Molecules.
  31. Nuclear Physics: is an complete coverage of nuclear physics principals relevant to modern day nuclear physics usage, and comprehensive coverage of principals of particle detection and measurement.
  32. Optics:Geometrical Optics; Physical Optics; Fraunhofer Diffraction; Fourier methods in Optics; Optical instruments and fringe localization; The diffraction grating spectrograph; The Michelson Interferometer; The Fabry-Perot interferometer; Reflection at dielectric surfaces and boundaries; Polarized light.
  33. Particle Physics:This book includes theoretical aspects, with chapters outlining the generation model and a charged Higgs boson model as alternative scenarios to the Standard Model
  34. Plasma Physics:This introduction covers basic plasma phenomena, kinetic theory, gaseous electronics, single particle motions, magnetized plasmas, magnetohydrodynamics, MHD plasma waves, waves in isotropic plasma, and waves in cold magnetized plasma.
  35. Quantum Mechanics:Topics covered include the fundamentals of quantum mechanics, angular momentum, approximation methods, and scattering theory.
  36. Quantum Physics Books:Wave Mechanics; Fundamental Concepts of Quantum Mechanics; Quantum Dynamics; Angular Momentum; Approximation Methods; Symmetry in Quantum Mechanics; Theory of chemical bonding; Scattering Theory; Relativistic Quantum Mechanics.
  37. Statistical Physics:Laws of Thermodynamics; Kinetic approach and Boltzmann transport theory; Classical statistical mechanics; Quantum Statistical Physics; Phase transitions; Linear Response Theory; Renormalization group; etc.
  38. Thermal Physics:The content of the module is briefly presented. In this section you will fined a video file (QuickTime, movie) where the author of this module is interviewed about this module.(89 582 books)
  39. Thermodynamics:The author adopted the principles of conservation and degradation of energy as the fundamental laws of thermodynamics, and deduced the ordinary forms of these laws from those principles. Chapters I, II contain a general sketch of the most important facts and definitions of thermodynamics as based on experience.
  40. Solid State Physics:Solid state physics studies the structural, mechanical, thermodynamic, electrical, magnetic, and optical properties of (poly-)crystalline and non-crystalline solids(4 798 books)
  41.  WorldScientific.com:World Scientific publishes about 500 new titles a year and 120 journals in various fields. Many of its books are recommended texts adopted by renowned institutions such as Harvard University, California Institute of Technology, Stanford University and Princeton University.