Hello,

you can refer to the following books to prepare for NDA. 

Mathematics

Mathematics for NDA/NA: National Defence Academy and Naval Academy - RS Aggarwal

Study Package Mathematics NDA/NA Entrance Exam - Arihant

General Ability Test 

History Of Modern India (History) - Bipan Chandra

Science and Technology in India (Science and Technology) - Kalpana Rajaram: Spectrum

Social Problems In India (Indian Society – GS1) - Ram Ahuja

Objective General English for Competitive Exams - S.P. Bakshi

Read Best Books to Prepare for NDA here - https://competition.careers360.com/articles/best-books-prepare-for-nda-2018

Thank you!!!

HIiiiii

To crack NDA exam you need proper strategies:
Make a routine schedule your studies. stay dedicated towards your goal.Begin with the basics and be clear with all the basic concepts. Clear all your doubts from time to time. Balance your preparation, do not stress out. focus on solving precious year papers and sample papers to improve your result and speed.
Refer to following links for better details.
https://competition.careers360.com/articles/nda-application-form
https://competition.careers360.com/articles/nda-syllabus
https://competition.careers360.com/articles/nda-eligibility-criteria
https://competition.careers360.com/articles/how-to-prepare-for-nda-2018

Hope this helps.
Thanks!!