headliner hard parts

Soon, I will attempt to install a headliner. I have a set of bows (not sure if they are right, havent test fit them), and the clips that they set in. I read someplace about a wire or spring or some such that goes between the rear-most bow and the rear-most roof support. I can guarantee I dont have those - the headliner wasnt installed when we got the car - if I need them.

Aside from the headliner itself, are there any other parts that I need?