I'm writing an essay about the trials but I'm too broke to buy any books at the moment and many of the books I would need are not available in my country's libraries. I'm not asking you guys to write my essay for me but it would be awesome if someone could give me some secondary source quotes and possibly direct me at relevant primary sources. I'm particularly interested in 'Salem Possessed' by Boyer and Nissenbaum, John Demos' study and Carol F. Karlsen's 'The Devil in the Shape of a Woman'.
Hello there. Your question seems to be related to school work, so we just want to remind you, and any potential respondents, that our rules DO permit people to ask for help with their homework, so long as they are seeking clarification or resources, rather than the answer itself. This policy is further explained in this META Thread.
Additionally, while our users may be able to help you out here, we hope that you also will take the time to check out our six-part series, "Finding and Understanding Sources", which should hopefully prove to be helpful for you as you continue in your research.
How much time do you have left? One thing you might not be aware of is that public libraries (at least in the U.S., where I am assuming you are due to the paper topic) are keyed in to the Interlibrary Loan program. You can request the books that your library doesn't have!
By way of primary sources, of course, there is the Salem Witch Trials Documentary Archive and Transcription Project. Which you could have easily found by Googling "salem witch trials primary sources." It's the first result.