FIVE formulations of categorical imperative (Immanuel Kant)??

I don't have my library at hand, but if you look at The Foundation [Grundlegung] for a Metaphysics of Morals I think you should be able to find all of them.

Thanks for the link, though actually my teacher gave the exact link and I could only find three in there. I don't know why he's saying there's five formulations when everywhere I look there only seems to be three.
Someone gave me this link also, but some of them seem to be the exact same thing: http://www.phil.cam.ac.uk/u_grads/Tripos/Ethics/course_material/2_formul_cat_imp_05.pdf

I think those are correct.

Yes, they all say pretty much the same thing, but then Kant acknowledged that they were all formulations of the same principle.

Ok, I'll just go with those. He also asks for the three most important concepts of those formulations. I'm guessing it's self-interest, inclination, and duty, though I'm not entirely sure?