Perhaps you should try some spelling variations:
thiet danh » thien danh, thien anh, thien dang
nhung cong » dung cong, thong cong, hang cong
hoc thiet » hoc thieu, hoc thuyet, hoc hien
tranh cua » manh cua
doanh cua » doanh luan
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than

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 danh - canh ((tranh cua) OR (doanh cua)) nhung cong ((dan toan) OR (dan than)) cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thiet danh - canh ((tranh cua) OR (doanh cua)) nhung cong ((dan toan) OR (dan than)) cao".
• Adding a wildcard symbol may retrieve word variants: hoc thiet danh - canh ((tranh cua) OR (doanh cua)) nhung cong ((dan toan) OR (dan than)) cao*.