Ashok Singh. (2019). UPSC Civil services prelims: General studies-1. wiley.
Chicago-stil citatAshok Singh. UPSC Civil Services Prelims: General Studies-1. New Delhi: wiley, 2019.
MLA-referensAshok Singh. UPSC Civil Services Prelims: General Studies-1. wiley, 2019.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.