Perhaps you should try some spelling variations:
hanh trang » thanh trung, canh tranh, hanh trinh
hoc thieu » toc thieu, hoc hien
hanh tang » anh tang, hanh mang, hanh tung
trong ban » trong san, trong tan, trong quan
doc hieu » toc thieu, hoc hien
cua dung » cua dang, cua dong, qua dung
ban toan » bai toan, ban than, van toan
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: ((doc hieu) or (hoc thieu)) xanh - ((hanh tang) OR (hanh trang)) cua dung trong ban toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (hoc thieu)) xanh - ((hanh tang) OR (hanh trang)) cua dung trong ban toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (hoc thieu)) xanh - ((hanh tang) OR (hanh trang)) cua dung trong ban toan cao".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (hoc thieu)) xanh - ((hanh tang) OR (hanh trang)) cua dung trong ban toan cao*.