Singh, S. &. P. (2019). General studies for civil services preliminary examination 2019. McGraw Hill.
Chicago-čujuhus (17. p.)Singh, Surendra & Parmar. General Studies for Civil Services Preliminary Examination 2019. Chennai: McGraw Hill, 2019.
MLA-čujuhus (9. p.)Singh, Surendra & Parmar. General Studies for Civil Services Preliminary Examination 2019. McGraw Hill, 2019.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.