Today an anonymous person is kindly enough to inform me that I was wrong --
The following shows I successfully defined an ontology that imports SOUPA Document ontology, and which in turn imports SOUPA Person and SOUPA Time ontologies:
Screenshot-1
The following shows the class view of all classes that are imported from different ontology documents:
Screenshot-2
The following shows the property view of all properties that are imported from different ontology documents:
Screenshot-3
Update: after I had moved from Blogger.com to WordPress, I lost the comment from the anonymous person. For that reason, I no longer have a record of the instruction that he/she has given me. :-(

