Create Relationship Between Custom Posts

Hi,
First of all - Custom press is great because it is the only MU enabled custom post creator. Thanks for creating that.
I need relatioship between custom posts like Types or ACF provide..For example Books and Authors... When I Edit Books, I should be able to see the Author in the CPT edit page and if it is a one on one relationship should be able to edit it. pods enables it, but their CPTs are not mu enabled, so I need to use CustomPress.

Kindly let me know, if there is a way to link parent-child relationship, 2 way relatonship and one to many relationships in CustomPress.