For UPSC General Studies preparation, primary sources include standard textbooks and government publications. Notable texts include the NCERT series for fundamentals, along with books like Indian Polity by Laxmikanth and Economic Survey by the Government of India. Additionally, online platforms like PIB and PRS India provide valuable insights. Reading newspapers such as The Hindu or Indian Express is critical for current affairs. Integrated learning from these diverse sources ensures a comprehensive grasp of subjects necessary for the UPSC syllabus.