What are acceptable "relationships with referees"?

I am applying for a job and need to give referees, and their relationship with me. I am not sure how to phrase things. My referees are:

• A colleague in my department I publish with


• A previous boss in another university I still publish with


• Senior people in my field who I have not published with (yet)

None of those things seem formal enough! Is there standard phrases I should be using?