Start with high-confidence diwali books, then narrow by subgenre or adjacent topics.
Diwali: a Festival of Lights
Anita Yasuda
Happy Diwali!
Sanyukta Mathur, Courtney Pippin-Mathur
Diwali: Love and Light
Darshika Varma
Diwali
Hannah Eliot
It's Diwali!
Kabir Sehgal, Surishtha Sehgal
Garland of Lights
Chitra Soundar
