UCI's submissions will be made to UC eScholarship - currently this is still new. All content sent to Proquest for inclusion in Dissertations & Theses Fulltext Database
The major source is Dissertations and Theses Fulltext - the indexing and abstracting source of most submissions in North America and increasingly worldwide. Other sources include:
Contains 8+million documents. “This database provides fast and convenient access to the dissertations and theses available in OCLC member libraries worldwide. Many theses are available electronically, at no charge, directly from the publishing institution" WorldCat Dissertations & Theses. Requests for content can be made via ILL.