We've bookmarked these best books for a Senior Leader to read.
Happy reading!
They are in no particular order.
The Craft of Assessment by Michael Chiles

Can be found on Amazon here:
Wiliam & Leahy's Five Formative Assessment Strategies in Action- Kate Jones

More information can be found here.
Inside the Black Box: v. 1: Raising Standards Through Classroom Assessment- Dylan William and Paul Black

More information can be found here.
The researchED Guide to Assessment- Sarah Donarski

More information can be found here.
A Little Guide for Teachers: Efficient Marking- Claire Gadsby

More information can be found here.