Hi @JamesStrong,
I'm not familiar with the Realize It platform, but even if I was, my advice would be to ask your teacher about their preferred citation format. I'm sure some people here in the global Canvas Community could offer some suggestions, but your teacher will ultimately be the one reading and grading your work, so it would be safer for you to use their preferred format rather than other suggestions which could cause you to get a lower grade.
-Chris
