I'm looking for a formulas book.

I'm currently student in Communication Systems and we have several courses involving mainly complex analysis, fourier analysis, signal processing, information theory and sometimes other principles and I need a lot of books for all these formulas.

Does someone knows a book with these formulas inside ?

It doesn't need to have demonstration or long explanation, I just need something to replace the stack of books I have.

The *best* one I found so far is the Gieck, but there are more than a half of the book I'll never use. I want something more specific for signal processing and information theory.