Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
chieu sang » chieu sach, chieu xanh, hieu lang
doi chieu » doc hieu, doi chi, ho chieu
hanh luan » khanh luan, hanh luat, han luan
hang luan » tang luan, dung luan
dang cong » dung cong
tran tap » toan tap, tran tan, tran tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi chieu sang - ((hanh luan) OR (hang luan)) va ((nhung cong) or (dang cong)) tan tran tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sang - ((hanh luan) OR (hang luan)) va ((nhung cong) OR (dang cong)) tan tran tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi chieu sang - ((hanh luan) OR (hang luan)) va ((nhung cong) or (dang cong)) tan tran tap".
• Adding a wildcard symbol may retrieve word variants: doi chieu sang - ((hanh luan) OR (hang luan)) va ((nhung cong) or (dang cong)) tan tran tap*.