Perhaps you should try some spelling variations:
thanh trung » thanh tung
thiet tach » chiet tach, thien hach, thuat tach
cong thanh » dong thanh, cong trinh, cong tan
trung cua » truong cua, trung tuan, trung cap
so thiet » soc thiet, hoc thiet, hoa thiet
cong san » cong tac
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: so thiet tach - thanh trung cua ban ((cong thanh) or (cong san)) toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so thiet tach - thanh trung cua ban ((cong thanh) OR (cong san)) toan cau*.