user: ### NOW ANSWER:
Question: What unit is located in China and has Zhou Zhang as an author?
Columns: ['Name', 'Status', 'Authors', 'Unit', 'Location', 'Notes']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Apsaravis', 'Valid', 'Norell Clarke', 'Djadokhta Formation', 'Mongolia', 'The type species is Apsaravis ukhaana.']
SQL:

assistant: SELECT "Unit" FROM "Table" WHERE "Location" = 'China' AND "Authors" = 'Zhou Zhang';