Google Scholar

Google Scholar indexes academic papers, theses, books and citations across disciplines and publishers, making it the usual starting point for literature searches.

Its most useful feature is citation tracking: each result shows how many works cite it and lets you browse them, which is how you find where a field moved after a foundational paper. Author profiles collect a researcher's output and citation counts in one place.

Be aware that coverage includes preprints and unrefereed material alongside peer-reviewed work, and citation counts are automated — treat them as a rough signal of influence rather than a quality guarantee.