Resources that can help in understanding international law for the UPSC exam include standard textbooks like "Introduction to International Law" by Anthony Aust and "International Law" by Malcolm N. Shaw. Online platforms like Unacademy and Coursera offer courses on international relations and law. Journals such as the American Journal of International Law provide contemporary perspectives. Additionally, following reputed blogs, podcasts, and participating in webinars can enhance understanding and application of international law concepts in UPSC contexts.