I'm going to study fourier analysis with Stein & Shakarachi's 'Fourier Analusis'. However, I want another textbook on fourier analysis to use as an auxiliary textbook. I want some books on fourier analysis that have similar things with Stein's, so it can help me studing main textbook(stein).
I'm considering Folland's 'Fourier analysis and its application', but I'm not sure that it can help me studing Stein's.
Can you recommend me a suitable book? For help, I already studied analysis(+multivariable), complex analysis, and some of real analysis.
I will recommend you a book 'An Introduction to Harmonic Analysis' written by Yitzhak Katznelson. It will be a little simpler to Stein's textbooks.