Perhaps you should try some spelling variations:
thiet tach » chiet tach, thien hach, thuat tach
hung luong » hung vuong, dung luong, hang luong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
luong tap » luong tai, cuong tap, luong tham
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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 ((trong van) or (trong cac)) hung luong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thiet tach - thanh ((trong van) OR (trong cac)) hung luong tap toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc thiet tach - thanh ((trong van) or (trong cac)) hung luong tap toan cau*.