Primary sources for general studies preparation for UPSC include NCERT textbooks, standard reference books, and government publications. Key texts like Laxmikanth's “Indian Polity,” and Ramesh Singh's “Indian Economy” provide comprehensive coverage of relevant topics. Additionally, resources like the India Year Book and reports by think tanks offer up-to-date information. Online platforms offering quizzes and video lectures further augment traditional study materials. A diverse range of sources can ensure aspirants develop a holistic understanding of subjects critical for clearing the UPSC examination.