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