Knee Jerk Reflex (Patellar Reflex)
Here's your citation in American Psychological Association (APA) format:
Knee Jerk Reflex (Patellar Reflex). (n.d.). In Alleydog.com's online glossary. Retrieved from: https://www.alleydog.com/glossary/definition-cit.php?term=Knee+Jerk+Reflex+%28Patellar+Reflex%29