Perhaps you should try some spelling variations:
trong huong » trong thuong, trong chuong, truong huong
hanh truong » hanh trong, anh truong, manh truong
hieu lang » chieu sang, hieu quang, nhieu tang
truong va » truong dai, truong cao, truong dao
va trong » va truong, va thong, va tuong
dan toan » van toan, dan than, manh 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 ((chinh sach) or (hieu lang)) - hanh truong va trong huong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chinh sach) OR (hieu lang)) - hanh truong va trong huong dan toan cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((chinh sach) or (hieu lang)) - hanh truong va trong huong dan toan cau*.