As you begin looking for resources for your presentation on Persuasion and Mary Prince, make sure to look at the materials listed on the Research tab of this guide. More general resources are listed there, while resources linked below will be more focused on the two works/authors for this group.
Don't forget to utilize the bibliographies and citations from resources that you find. If a scholar is writing about a topic that interests you, consult the resources that they used. That's part of the reason that there are citations! You can find many great sources in the bibliographies of your required readings and other publications relating to your topic or author.