www.boyesturner.com/article/mutual-and-mirror-wills-the-same-or-similar
See also:
hsfnotes.com/pwtd/2022/09/26/the-binding-contract-requirement-the-county-court-considers-the-test-for-mutual-wills/#page=1
www.hilldickinson.com/insights/articles/undoing-mutual-wills-agreements
gatehouselaw.co.uk/when-undue-influence-and-mutual-wills-collide-naidoo-v-barton-2023-ewhc-500-ch/