Topics_include_Butterworth,_Chebyshev,_Bessel,_and_elliptical_filters_with_C_routines_for_computing_frequency_and_impulse_and_step_responses;_discrete_time_systems;_FIR_filter_design_with_the_Fourier_series_method_with_C_routines_for_Hamming,_Hanning,_Bartlett,_and_Dolph-Chebyshev_window_functions;_IRR_filter_design_with_C_routines_