NCERT books/course books prescribed by the CBSE/ICSE/state boards can be referred to for preparation. Also, the following can be consulted MTG class-wise workbooks (For classes 1 to 12), SOF Olympiad Trainer mobile apps, Olympiad Skill Development System (OSDS), previous years' papers, Olympiad books of reasoning (for preparation for the reasoning section of Olympiads), 100% real test papers, E-Quiz, and various magazines like Chemistry Today, Biology Today, Mathematics Today and Physics For You.