A new book coming out this summer- Grading for Growth by David Clark and Robert Talbert- both are math profs at grand valley state
https://styluspub.presswarehouse.com/browse/book/9781642673814/Grading-for-Growth

They have a website https://gradingforgrowth.com/
Talbert has a separate blog https://rtalbert.org/tag/mastery-grading/