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