Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
trung cap » truong cao, trung tam
dung cong » dung trong
khoan cam » khoa cam, khoan va, phan cam
ho thiet » hoc thiet, hoa thiet, so thiet
dung cua » dung luan, dung cho
cong san » cong tac
khan cap » khan ap, than cap, phan cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho thiet tach - thanh ((dung cua) or (trung cap)) dung cong san ((khan cap) OR (khoan cam))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho thiet tach - thanh ((dung cua) OR (trung cap)) dung cong san ((khan cap) OR (khoan cam))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho thiet tach - thanh ((dung cua) or (trung cap)) dung cong san ((khan cap) OR (khoan cam))*".