Need for a domain text corporus

Hello there. I'm searching for a text corpus describing a particular domain (i.e. biomedical, bioinformatics, ecc) but I need it to be not that large, as we need to analyze it first and then run our experiments (I'm working in NLP with a strong focus on knowledge extraction). Up to now, I have only found large language corpora, which are not fitting my requirements. Any advice? Thanks in advance.

EDIT: in the title it's corpus, of course.