Hi wittyarif,

I love that you find the Khan Academy AP calculus and AP statistics videos useful. For extra reading material, you can take a look at these two links to find books or flashcards for calculus and statistics

AP Calculus: https://www.examshazam.com/advanced-placement/best-ap-calculus-ab-books/

AP Statistics: https://www.examshazam.com/advanced-placement/best-ap-statistics-books/

Barrons have been a very good brand for books like these. Hope  I have helped you today

Sincerely,

TheUnderratedProgrammer