Mahabir Singh. (2019). IMO - OLYMPIAD WORK BOOK - 5 (2019-20.). MTG Learning Media.
芝加哥风格引文Mahabir Singh. IMO - OLYMPIAD WORK BOOK - 5. 2019-20. MTG Learning Media, 2019.
MLA引文Mahabir Singh. IMO - OLYMPIAD WORK BOOK - 5. 2019-20. MTG Learning Media, 2019.
警告：这些引文格式不一定是100％准确.