Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
hang cong » dang cong, hang nong, thanh cong
bang cong » dang cong, bang song, dung cong
so thiet » soc thiet, hoc thiet, hoa thiet
tinh cua » trinh cua, sinh cua, tinh chat
van tuan » van quan, van ban, anh tuan
tuan tap » toan tap, tuan tai, tuyen 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 - hanh tinh cua ((hang cong) or (bang cong)) van tuan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so thiet tach - hanh tinh cua ((hang cong) OR (bang cong)) van tuan tap*.