Some books which migh be helpful
Topology
Luke G., Mishchenko A.,
Vector bundles and their applications
Anatoly Fomenko, Dmitry Fuchs
Homotopic topology
Michael Atiyah
K-Theory
John Milnor, James D. Stasheff
Characteristic classes
Differential and complex geometry
Arthur L. Besse
Einstein Manifolds
Andrei Moroianu,
Lectures on Kahler Geometry
Jean-Pierre Demailly,
Complex Analytic and Differential Geometry
Liviu Ornea, Misha Verbitsky,
Principles of Locally Conformally Kahler Geometry,
K3 surfaces
Geometrie riemannienne en dimension 4
(Seminaire Arthur Besse 1978/79).
Daniel Huybrechts
Lectures on K3 Surfaces
A. Beauville,
Complex algebraic surfaces
Misha Verbitsky, K3 surfaces
IMPA