Polish Space
Separable Space
Hausdorff Space
Banach Space
AnIntroduccToSobolevSpaces[1]
Problems in TopoElementary Topology by O. Ya. Viro , O. A. Ivanov , N. Yu. Netsvetaev , and V. M. Kharlamov
Visual Introduction to Measure Theory
Fem
Notes on PDE
Notes on Analysis