Resources for enhancing knowledge of international relations for UPSC include standard textbooks, scholarly articles, and reputable online platforms. Aspirants should focus on crucial topics such as global governance, security issues, and diplomacy. Engagement with current affairs through newspapers and journals like The Economist or Foreign Affairs can provide contemporary insights. Additionally, attending online webinars or lectures by experts can deepen understanding. Studying past UPSC papers related to international relations can help identify recurring themes and essential areas of focus, enabling candidates to develop a well-rounded perspective for their preparation.