When searching ProQuest Dissertations & Theses Global, you can add the terms "qualitative" or "mixed methods" to your topic. For example, if you are looking for dissertations in the area of organizational change and leadership, you can type "organizational change and leadership and mixed methods" in the search box (without quotes).
1) You will need to choose the Dissertations database from a list of other Proquest Databases:
1a) If the screen looks like the one below, then you would click on "Databases," then choose the Dissertations database.
2) Before you complete your search, check the box under the search box that says "Doctoral Dissertations only:"
3) After you complete your search, you can limit by date using the "Enter a Date Range" option on the left menu (Staring and Ending dates). Then click Update.