Babbling+%28babbling+stage%29
Here's your citation in American Psychological Association (APA) format:
Babbling+%28babbling+stage%29. (n.d.). In Alleydog.com's online glossary. Retrieved from: https://www.alleydog.com/glossary/definition-cit.php?term=Babbling%2B%2528babbling%2Bstage%2529