A great tool for citations is available right inside of Google Docs! See directions here:
https://support.google.com/docs/answer/10090962?hl=en&co=GENIE.Platform%3DDesktop
Other free resources include:
EasyBib.com
MyBib.com
Still need help? Come see Mx. Rothstein during lunch, or send an email for more support (arothstein6@schools.nyc.gov