Q:

Make Imported Library Internal

I have a DB repository library which I import to another library project. 
The DB library contain public models which I don't want it to be exposed to other projects that use the second library
is there's any trick that would help me do so? 

A:

Not with public classes.  But if your assemblies are strongly signed then you could use the InternalsVisibleTo attribute and make those classes internal.  The idea of this attribute is that you can place it in your DB library assembly and include a list of other assemblies that will see internal classes as if they were public.