एपीए उद्धरण

Surender Singh. (2019). General Studies Paper I for Civil Services Preliminary Examination. McGraw Hill Education Pvt Ltd.

शिकागो स्टाइल उद्धरण

Surender Singh. General Studies Paper I for Civil Services Preliminary Examination. Chennai: McGraw Hill Education Pvt Ltd, 2019.

एमएलए उद्धरण

Surender Singh. General Studies Paper I for Civil Services Preliminary Examination. McGraw Hill Education Pvt Ltd, 2019.