For advanced calculus problem-solving, users are seeking websites that cover topics like Fourier series, linear algebra, and differential geometry. However, it is noted that many of these subjects fall outside the scope of advanced calculus, which primarily includes concepts like partial derivatives, multiple integrals, and series convergence. The discussion highlights the difficulty in finding quality resources, as many comprehensive sites are restricted to university students. It is suggested to utilize Google to search for PDF files, which often provide valuable textbook-style content. Overall, the search for effective advanced calculus resources remains challenging.