Published tests are commercially available through test publishers. Use of these instruments is through purchase from the publisher, meeting the criteria for the purchase and administration of that test.
Unpublished tests are instruments that are not commercially available and are found in journal articles, ERIC documents, dissertations, or test compilation volumes. Use of these tests often requires contacting the author for permission.
Additional information can be found on APA's webpage, Finding Information about Psychological Tests
Michener Library retains some print copies of tests behind the main desk. Items in this collection may be restricted and/or require instructor permission to use. To search the collection, search the library catalog and then under "Refine by" in the left menu, go to "Location" and select "Mich Tests."