Challenges to Internal Security of India Courseware, 7e for UPSC CSE Main 2025-26 by Ashok Kumar (IPS Retd.) & Vipul Anekant (DANIPS) | 20+ Online Conceptual Videos | 60+ Upsc Main Practice Questions | Full Colour ebook | Chapterwise PYQs (2013-2024) | Model Answers (2023-2024 PYQs) | Quick Revision