https://qualifications.pearson.com/c...mulae_Book.pdf
https://www.thestudentroom.co.uk/showthread.php?t=5747896
https://www.thestudentroom.co.uk/a-level/exams/how-to-revise-a-level-maths-new-spec
(includes digital textbook)
https://drive.google.com/drive/folders/0B1ZiqBksUHNYX3dkQXFRQ0NlNDA