https://teacherhead.com/2018/09/02/great-teaching-the-power-of-expectations/
https://teacherhead.com/2019/01/24/rescuing-differentiation-from-the-checklist-of-bad-practice/
https://furtheredagogy.wordpress.com/tag/stretch-and-challenge/
https://learningspy.co.uk/assessment/differentiation-to-do-or-not-to-do/
https://chrismoyse.wordpress.com/2014/04/18/a-rough-guide-to-differentiation/