This the book "Signals and Systems - made ridiculously simple" by J. Karu in djvu file format. It gives an excellent introduction to system theory and covers all related concepts: Continuous-Time Systems, Frequency Domain, Laplace Transform, Continuous-Time System Analysis, Bode Plots, Discrete Signals, z-Transform, Discrete-Time Systems, Generalized Functions, Impulse Response & Convolution, Discrete-Time Convolution, Continuous-Time Convolution, Deconvolution, Causality and Stability, Feedback, Fourier-Transform, Filters, Modulation, Sampling, Fourier Series, Appendix with Derivations.-This is the book "Signals and Systems- made ridiculously simple" by J. Karu in djvu file format. It gives an excellent introduction to system theory and covers all related concepts: Continuous-Time Systems, Frequency Domain, Laplace Transform, Continuous-Time System Analysis, Bode Plots, Discrete Signals, z-Transform, Discrete-Time Systems, Generalized Functions, Impulse Response & Convolution, Discrete-Time Convolution, Continuous-Time Convolution, Deconvolution, Causality and Stability, Feedback, Fourier-Transform, Filters, Modulation, Sampling, Fourier Series, Appendix with Derivations.