Deep Learning textbook by Ian Goodfellow, Yoshua Bengio and Aaron Courville: Chapter 1 - Introduction
Understanding Deep Learning book by Simon J.D. Prince: Chapter 1. The book is currently (checked on 23/01/2024) available for a free download (download page)
Bigger batches are not necessarily better by Keshar et al., On Large-Batch Training for Deep Learning: Generalization Gap and Sharp Minima, ArXiv, 2017.