Perhaps you should try some spelling variations:
hanh trung » thanh trung, hanh trang, manh trung
chieu sang » chieu sach, chieu xanh, nhieu tang
hieu lang » hieu quang, nhieu tang, hieu van
cong dan » cong san, cong tan, huong dan
dan chan » dan gian, dan ca, van chat
chan nan » chan nhan, chang nang, chan doan

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua nhung) or (va nhung)) cong dan chan nan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua nhung) OR (va nhung)) cong dan chan nan.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua nhung) or (va nhung)) cong dan chan nan".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (hieu lang)) - hanh trung ((cua nhung) or (va nhung)) cong dan chan nan*.