For information about requesting print books for free home delivery within the continental U.S., please see https://libguides.umgc.edu/books/request
You can find previous UMGC/UMUC students' dissertations in the Dissertations and Theses Global (ProQuest) database.
Enter "university of maryland global campus" OR "university of maryland university college" into a search box and use the drop-down menu next to the search box to select University/institution - SCH. (Note that the university was known as University of Maryland University College prior to July 1, 2019, so most previous doctoral students' dissertations can be found by using that name.)
Note that you can also find some previous students' dissertations in UMGC's Digital Repository.