You can refer this books for GST and DAT.

GST Books for students:

1) GST Guide for students: Making GST -good and simple tax.

2) Goods and services Tax law book for students.

3) Taxmann's GST Mini ready reckoner.

4) GST for the layman:How it impacts your daily life.

5)Taxmann's students guide to income tax including GST.

Advance books of GST:

1)Summary book of GST.

2)Taxmann's GST new return's: How to meet your obligations.

3)Taxmann's GST Audit and Annual Returns.

4)Comprehensive guide on indirect Tax laws,GST,customs and FTP.

5) Taxmann's GST acts with rules and forms.

DAT Prep Books:

1) Kaplan DAT Prep Plus.

2) Mometrix Test Preparation DAT Prep book

3) The Princeton review cracking the DAT.

4) Sterling Test Prep DAT.

5) The gold standard DAT Prep book.