Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hanh dung » thanh dung, anh dung, hanh dong
phan cong » thanh cong
thanh lap » thanh san, phan lap, thanh hai
cong tac » cong ty
toan lap » toan tap, toan lao, toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thiet tach - hanh dung ((phan xuong) or (phan cong)) cong tac ((toan lap) or (thanh lap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - hanh dung ((phan xuong) OR (phan cong)) cong tac ((toan lap) OR (thanh lap)).
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - hanh dung ((phan xuong) or (phan cong)) cong tac ((toan lap) or (thanh lap))*.