Παραπομπή APA

Ashok Singh. (2019). UPSC Civil services prelims: General studies-1. wiley.

Παραπομπή Chicago Style

Ashok Singh. UPSC Civil Services Prelims: General Studies-1. New Delhi: wiley, 2019.

Παραπομπή MLA

Ashok Singh. UPSC Civil Services Prelims: General Studies-1. wiley, 2019.