importing a namespace that contains multiple xsd files

Suppose I have namespace called: 

   http://www.foo.com/namespace1/ 

which consists of the files: 

   http://www.foo.com/namespace1/file1.xsd 
   http://www.foo.com/namespace1/file2.xsd 

I want to access constructs that are defined in BOTH files in another schema associated with a different namespace (say http://www.foo.com/namespace2) using <import>.  How do I use  schemaLocation in the "namespace2" schema to access BOTH files?

thanks in advance, Chuck