Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
thanh sinh » thanh binh, thanh tinh, thanh vinh
hang cong » dang cong, hang nong, thanh cong
bang cong » dang cong, bang song, dung cong
so thiet » soc thiet, hoc thiet, hoa thiet
sinh cua » manh cua, dinh cuu, sinh va
van tan » van tuan, van ban, van tai
tan tap » toan tap, han tap, tan tat

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 sinh cua ((hang cong) or (bang cong)) van tan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so thiet tach - thanh sinh cua ((hang cong) OR (bang cong)) van tan tap*.