Atomic Habits is a NYT #1 Bestseller full of easy to implement tips. Specific to this sales people, there are several sales related habits referenced in the book like a mental connection between calls made and two jars of paperclips. Find out why certain mental tricks help you create better habits and stay on track with your goals. 

Atomic Habits isn't an academic book, per se but there are lots of research related references throughout the book.