My girlfriend and I rented a apartment and have recently separated. The rental agreement is in my name only and all rent receipts are in my name. She refuses to leave the apartment. She does not pay any of the rent. I continue to pay the rent and have not taken my name off the agreement. I want her to move out so I can continue to live in the apartment. Does she have any legal right to occupy the residency? Where can I find the necessary information to back this up?

Since she has lived there along with you she is considered a resident. However, since yours is the only name on the lease, you are her landlord and she is a periodic (month to month) tenant.

So you have go through formal eviction proceedings. Check with your local housing court for the exact procedure. But generally you will need to give her notice that you are terminating her tenancy. You may need to give one full rental period as notice. If she refuses to vacate when the deadline ends, you will need to file in court for an eviction order. This will involve a hearing where the eviction order will be given. If she still refiuses to leave, you will need to hire a sheriff to physically remove her.