Perhaps you should try some spelling variations:
hoc thieu » toc thieu, hoc hien
manh tung » manh hung, thanh tung
hang cong » dang cong, hang nong, bang cong
ho chieu » theo chieu, doi chieu, mot chieu
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than
tung va » trung va, tuong va, dung va
va hang » van hang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho chieu) OR (hoc thieu)) tinh - manh tung va hang cong ((dan toan) or (dan than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho chieu) OR (hoc thieu)) tinh - manh tung va hang cong ((dan toan) OR (dan than)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) OR (hoc thieu)) tinh - manh tung va hang cong ((dan toan) or (dan than)) cao".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) OR (hoc thieu)) tinh - manh tung va hang cong ((dan toan) or (dan than)) cao*.