Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hanh trinh » hanh chinh
nhung cong » dung cong, thong cong, nhung don
hoc thieu » toc thieu, hoc hien
hang cong » dang cong, hang nong, bang cong
tap toan » tap doan, tap quan, bai toan
toan ban » van 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 thieu xanh - ((hanh trinh) OR (canh tranh)) va ((nhung cong) or (hang cong)) tap toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - ((hanh trinh) OR (canh tranh)) va ((nhung cong) OR (hang cong)) tap toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - ((hanh trinh) OR (canh tranh)) va ((nhung cong) or (hang cong)) tap toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - ((hanh trinh) OR (canh tranh)) va ((nhung cong) or (hang cong)) tap toan ban*.