Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
hieu quang » thieu quang, hieu quan, hieu qua
hanh trung » thanh trung, hanh trang, manh trung
cong thanh » dong thanh, cong trinh, truong thanh
trung va » truong va, trang va, trung ha
cong tan » cong tac, cong san, cong ty
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: ho ((chieu sang) or (hieu quang)) - hanh trung va nhung ((cong thanh) OR (cong tan)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sang) OR (hieu quang)) - hanh trung va nhung ((cong thanh) OR (cong tan)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu sang) or (hieu quang)) - hanh trung va nhung ((cong thanh) OR (cong tan)) toan cao".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sang) or (hieu quang)) - hanh trung va nhung ((cong thanh) OR (cong tan)) toan cao*.