Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
thanh tung » thanh cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
hang cong » hang nong, bang cong, thanh cong
dang cong » dung cong
tung cam » dung cam, trung cap, tung pham
than cau » toan cau, phan cau, than cap
phan cac » nhan cach, phan dau, phan lap

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 - thanh tung cam ((hang cong) or (dang cong)) dan ((than cau) or (phan cac))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - thanh tung cam ((hang cong) OR (dang cong)) dan ((than cau) OR (phan cac)).
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - thanh tung cam ((hang cong) or (dang cong)) dan ((than cau) or (phan cac))*.