Great but difficult book
Oppenheims Signals and systems is a hard to read book, but if you get through it it'll be 100% worth your time. It covers alot of the topics you will need for future courses such as Digital Signal Processinfg and Digital Image Processing. Allthough the coverage on control could be more elaborate, it does a great job at Z-Transforms, Fourier Transforms, and Laplace Transforms, both in continous and Discrete time. I always find myself coming back to this book since it has such a detailed description of these topics. So, allthough hard to get through, for those who are up to it, you won't regret the journey in the end.
