If you're looking for a solid "real world" book on op-amps and their applications, this is a great reference book. It contains useful examples that teach the underlying theory without being overly burdened with graduate level mathematics.
Op-Amps and Linear Integrated Circuits
Electronics Devices And Circuits
Microelectronic Circuits
Integrated electronics : Analog and Digital Circuit and system
Electrical Engineering (GATE Solved Papers)
The Performance And Design Of Alternating Current Machine