For your debate about the Geocentric vs Heliocentric model of the universe, you are expected to use information that was available at the time of Copernicus (1473-1543). To identify what documents were available at that time or prior to that time, you will need to start by reading more contemporary literature that references these sources. These more contemporary works might include the following:
You may find books and journal articles cited in other works you read or you can search for them using the library's main search engine, catalog, and databases.
In addition to the challenge of finding works available at the time of Copernicus, you will need to find them in a translated form so you can read them. Once you've identified a translated version of a work, use the library's catalog to see if it is in our collection. It could be part of a collection of works translated and published as a single volume or set of volumes.
A helpful online source is the Internet Archive. It sometimes has historic publications available in pdf format for download. Search the title of the work you've discoverd and see if it's there.
Here are two examples of works that can help inform your positions in this debate:
For Geocentrism, one relevant work is Ptolemy’s Almagest; we have the following in our print collection:
A work by Plato (Myth of Er, a section of the Republic) is said to describe the cosmos as the Spindle of Necessity supporting geocentrism. The library has Plato’s Republic in print and ebook formats.
For Heliocentrism, Copernicus’ On the Revolutions of the Heavenly Spheres is noted.