Kasper, Katie. "US Regions Sort". OER Commons. Institute for the Study of Knowledge Management in Education, 17 May 2018. Web. 01 May 2024. <https://wlresources.dpi.wi.gov/authoring/386-us-regions-sort>.
Kasper, K. (2018, May 17). US Regions Sort. OER Commons. Retrieved May 01, 2024, from https://wlresources.dpi.wi.gov/authoring/386-us-regions-sort.