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