request info on Topos

Hello, I´m beginning a MSc course on Computer Science. I started working with categories (specially topos)and coherence spaces and I´m looking for some papers and basic references on this subject. I´d be glad if you could help me. The main goal of my work is to define the categories (or subcategories) of STAB (coherence spaces and stable functions) and LIN (coherence spaces and linear functions) as Topos. Any suggestions are welcome. Thanks in advance, Simone Costa.