TY  - BOOK
AU  - Agrahari Ravi P
TI  - Science and Technology for civil Services Preliminary and main examinations 
SN  - 978-93-5532-632-4
U1  - 609.54139 AGR 
PY  - 2025///
CY  - Chennai
PB  - Mc Graw hill
KW  - Competivtive exam
ER  -