Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hoc thiet » hoc thieu, hoc thuyet, hoc hien
trang cua » tranh cua, trung cua, thang cua
tang cua » mang cua, hang cua, tang luan
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
toan ban » van ban

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: hoc thiet tach - hanh ((trang cua) OR (tang cua)) nhung ((cong tan) OR (cong san)) toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet tach - hanh ((trang cua) or (tang cua)) nhung ((cong tan) OR (cong san)) toan ban~".
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh ((trang cua) or (tang cua)) nhung ((cong tan) OR (cong san)) toan ban*.