Try logging in through BlueLink first, then clicking on the "DB lib" icon in the upper right corner.
Try logging in to the Subscription Services page of EZproxy. If this works, use your browser's search function and choose your database from the list.
Google Scholar for off-campus access to library subscriptions
PubMed offers a tool for connecting to library subscriptions. You will need to create an account and choose Oklahoma City University Dulaney-Browne Library (dashboard > site preferences > outside tool) or use the link from the library web page.