Knee pain, retrieved on 8 August 2020 from https://www.mayoclinic.org/diseases-conditions/knee-pain/symptoms-causes/syc-20350849. (7 March 2019)
What's causing my knee pain?, retrieved on 8 August 2020 from https://www.webmd.com/pain-management/knee-pain/knee-pain-causes#1. (n.d.)
Hettrich CM, Liechti D. Patellofemoral pain syndrome, retrieved on 8 August 2020 from https://orthoinfo.aaos.org/en/diseases--conditions/patellofemoral-pain-syndrome/. (February 2015)
Beutler A. Patient education: knee pain (beyond the basics), retrieved on 8 August 2020 from https://www.uptodate.com/contents/knee-pain-beyond-the-basics. (9 April 2020)
Osteoarthritis, retrieved on 8 August 2020 from https://www.mayoclinic.org/diseases-conditions/osteoarthritis/symptoms-causes/syc-20351925. (22 February 2020)
ACL injury, retrieved on 8 August 2020 from https://www.mayoclinic.org/diseases-conditions/acl-injury/symptoms-causes/syc-20350738. (30 March 2019)
Anterior cruciate ligament (ACL) injuries, retrieved on 8 August 2020 from https://orthoinfo.aaos.org/en/diseases--conditions/anterior-cruciate-ligament-acl-injuries/. (n.d.)
Torn meniscus, retrieved on 8 August 2020 from https://www.mayoclinic.org/diseases-conditions/torn-meniscus/symptoms-causes/syc-20354818. (15 November 2019)