Depending on how much time you have for the paper, Inter-library loan is often useful, or if the University has access to them via electronic format (I usually like to read books in hard copy but you do what you have to when time is short).
If they were older books it would be a snap, Google’s Gutenberg Project is great for older books, and sometimes even has recent books.
For Journal Articles: in addition to the fact that academic journals tend to be bad in their understanding of anything “conservative” (note: this doesn’t mean you won’t find anything useful there; you might have more luck than I do. Plus it actually helps to have a few “bad critics” to beat up on for getting things wrong), they’re “secondary sources.” But there are also online publications where neoconservatives tend to publish – “The National Interest,” “The Public Interest,” “Policy Review,” “The New Criterion,” “The Clairmont Institute,” “Commentary,” and “National Affairs.” If you can get access to their archives (www.unz.org might be helpful for at least some neoconservative publications) you can mine these. Also, AEI publications and some of the publications of the Hoover Institution. (Note with all of the above, not necessarily every article is written from a neoconservative perspective. Plus, you’ll have to find the key ones to read & cite; for example, this relatively recent one).
Also, I should have mentioned this earlier: the most useful tool in the world are the footnotes and bibliographies/cited sources in any of the books and articles you read. Whenever you see an author cite something interesting written by someone else, you can follow that bread-crumb and pick up that source (be it book or article) as well. If you do this, quite often the problem transforms from “how can I find enough sources?” to “I have so many to read, how do I prioritize which ones so I can finish reading them in time to write?”