Ashok Singh. (2019). UPSC Civil services prelims: General studies-1. wiley.
シカゴスタイル引用形Ashok Singh. UPSC Civil Services Prelims: General Studies-1. New Delhi: wiley, 2019.
MLA引用形式Ashok Singh. UPSC Civil Services Prelims: General Studies-1. wiley, 2019.
警告: この引用は必ずしも正確ではありません.