I don’t have full stats for all my kindle-direct sales, but am surprised how steady the sales for the GA book have been

Jan 1- March 31 2019 April 1 – June 30, 2019 June 4 – Sept 1, 2019

Geometric Algebra for Electrical Engineers

24 24 26

Statistical Mechanics

3 2

Relativistic Electrodynamics

2

Classical Optics

4

Quantum Field Theory

2 2

Condensed Matter

1

Graduate Quantum Mechanics

1

Some of the earlier sales were to family members who wanted copies, but the rest are legitimate.