Up to 20 books are listed, in descending order of popularity at this site

Computer science / Mathematical physics / Discrete mathematics / Pure mathematics / Combinatorics / Mathematical analysis / Geometry & topology / Algebraic geometry / Applied / Programming / Geometry, algebraic / Differential equations, partial / Combinatorial analysis / Algorithms / Graph theory / Surfaces

Solid-state physics / Electromagnetism / Experiments, instruments & measurement / Electron microscopes & microscopy / Science & math / Biological sciences / Materials & material science / Testing / Electrical & electronics / Crystallography / Surfaces (physics) / Electrons--diffraction / Crystal optics / Thin films--optical properties / Solid state physics / Solid state chemistry