หน่วยใดตั้งอยู่ในประเทศจีนและมี Zhou Zhang เป็นผู้เขียน?ไม่จำเป็นต้องใช้ตารางทั้งหมด
What unit is located in China and has Zhou Zhang as an author?It is not neccessary to use all the tables.
 table_39801:  "Name" [ text]  "Status" [ text]  "Authors" [ text]  "Unit" [ text]  "Location" [ text]  "Notes" [ text] 
SELECT "Unit" FROM table_39801 WHERE "Location" = 'china' AND "Authors" = 'zhou zhang'