Perhaps you should try some spelling variations:
hanh truong » hanh trong, manh truong, chinh truong
anh truong » manh truong, anh thuong, anh trong
hieu lang » chieu sang, hieu quang, nhieu tang
quan dung » quang dung, quan duong, qua dung
hoc hieu » hoc thieu, hoc hien, doc hieu
cong dan » cong tan, huong dan, cong dong
cong san » cong tac
toan tap » toan 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 hieu lang - ((hanh truong) OR (anh truong)) quan dung ((cong dan) or (cong san)) toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - ((hanh truong) OR (anh truong)) quan dung ((cong dan) OR (cong san)) toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hieu lang - ((hanh truong) OR (anh truong)) quan dung ((cong dan) or (cong san)) toan tap".
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - ((hanh truong) OR (anh truong)) quan dung ((cong dan) or (cong san)) toan tap*.