ProQuest controls the embargo length on dissertations in their database, and typically has a maximum embargo length of two years. Contact them at disspub@proquest.com to request that your embargo be extended for additional years. 

This will not extend your embargo on your dissertation in D-Scholarship@Pitt. To inquire about extending your embargo in D-Scholarship, contact our team at etd-support@pitt.edu.

Note that most publishers do not consider institutional dissemination of theses and dissertations to constitute prior publication.  You can find out more about ETDs and future publication potential for graduate students via the Networked Digital Library of Theses and Dissertations Web site at http://www.ndltd.org/resources/manage-etds/publishers-and-etds.