Perhaps you should try some spelling variations:
trung tuan » trung thanh, trung tam, truong thanh
tran tuan » tran xuan, tran quang, tran thanh
dung cong » dung trong
kha nang » phap nang, ky nang, ki nang
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan cau » toan cao, toan ban, toan tap

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chuc nang) OR (kha nang)) - thanh ((trung tuan) OR (tran tuan)) dung cong san toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chuc nang) or (kha nang)) - thanh ((trung tuan) OR (tran tuan)) dung cong san toan cau~".
• Adding a wildcard symbol may retrieve word variants: ho ((chuc nang) or (kha nang)) - thanh ((trung tuan) OR (tran tuan)) dung cong san toan cau*.