Mail resident and non-resdient return for NJ tax

I'm a part-year resident of NJ so I need to file two returns: NJ 1040 and NJ 1040 NR so I cannot do efile. When I mail the return, can I put those two returns in the same envelop? Also I have a refund for both returns, could I using the private delivery services (such as UPS) to mail them to:

State of New Jersey
Division of Taxation
Revenue Processing Center
200 Woolverton Street
Building 20
Trenton, NJ 08611

The NJ division of tax mentioned putting only one return in one evelop but my case is the two returns are for the same person so just want to make sure. Thank you!