Author. (Date). [Map description]. Retrieval information
Example—reference list entry
Google. (n.d.). [Google map of Wintec City Campus Hamilton]. Retrieved November 22, 2018, from https://www.google.com/maps/place/Wintec+City+Campus/@-37.7888704,175.276469,17z/data=!3m1!4b1!4m5!3m4!1s0x6d6d18a57fa16281:0x72b05e2e8812d179!8m2!3d-37.7888704!4d175.2786577
Note: When referencing Google maps, include a retrieval date as the map is likely to change. Use (n.d). as these maps are generated in the moment, and don't have a specific publication date.