Graduate theses and doctoral dissertations held in university repositories and other Open Educational Resources (OER) are forms of grey literature and can be great sources of research to build upon. Although these types of papers don't go through the official peer-reviewed process, they still go through a rigorous process of review and editing by a faculty advisor or committee and are produced by students and faculty all around the world.
You can locate pieces from TWU students and faculty by searching the Repository @ TWU. Here you'll also find other pieces of grey literature, such as past conferences, Open Educational Resources, and a portion of the digital archives which include yearbooks and more.
Additional online databases for theses and dissertations:
British Library's Research Repository
Networked Digital Library of Theses and Dissertations
Open Access Theses and Dissertations
Below you'll find a list of individual repositories in alphabetical order to search: