My Swim Pro. https://myswimpro.com/blog/2020/09/23/how-to-swim-butterfly-with-perfect-technique/
Diakses pada 16 Januari 2020Swim England. https://www.swimming.org/masters/advanced-butterfly-stroke-technique/
Diakses pada 16 Januari 2020Swim Like A Fish. https://swimlikeafish.org/4-different-ways-to-butterfly-breathing-techniques
Diakses pada 16 Januari 2020