Perhaps you should try some spelling variations:
chieu xanh » chieu sach, chieu sang, chieu tinh
hieu quang » thieu quang, hieu quan, hieu qua
nhung cong » dung cong, thong cong, hang cong
hanh tang » hanh trang, hanh mang, hanh tung
cua nhung » va nhung
anh tang » anh bang, anh dang, anh nang
cong dan » cong san, cong tan, huong dan
dan chan » dan gian, dan ca, van chat
chan cau » phan cau, can cau, chinh cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((chieu xanh) or (hieu quang)) - ((hanh tang) or (anh tang)) cua nhung cong dan chan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((chieu xanh) OR (hieu quang)) - ((hanh tang) OR (anh tang)) cua nhung cong dan chan cau.
• Adding a wildcard symbol may retrieve word variants: doc ((chieu xanh) or (hieu quang)) - ((hanh tang) or (anh tang)) cua nhung cong dan chan cau*.