Question: Is there a tool that can help me find and download free PDFs of academic sources with advanced filtering options?

If you need a tool to search for and download free PDFs of academic papers with more sophisticated filtering abilities, Sourcely is worth a look. This AI-powered literature sourcing tool lets you paste in essays or paragraphs to get a list of relevant sources. It's got more advanced filtering options, like publication date, authorship and relevance, and you can download free PDFs of sources you're interested in. Sourcely also offers features like generating credible summaries, exporting references, and an interface that's been used by more than 10,000 students and researchers.

Another option is Consensus, an AI-powered academic search engine that indexes more than 200 million papers across all subjects. It's got proprietary search tools with filtering options like sample size, study design, methodology and availability. The service returns results that are linked to scientific sources, so you can dig into the original research papers. Consensus offers various pricing levels, including a free plan, so it's useful for students or researchers with modest needs.

If you want something more feature-rich, check out Semantic Scholar, a free AI-powered research service. It lets you search for and read relevant scientific papers in a database of more than 219 million papers across all scientific fields. Semantic Scholar has powerful search filters for journals, conferences, authors, paper types and date ranges, along with brief summaries (TLDRs) to help you evaluate papers. It also has tools to cite papers, organize papers into folders and create AI-powered research feeds.