Perhaps you should try some spelling variations:
hieu quang » thieu quang, hieu quan, hieu qua
thanh dung » thanh duong, thanh tung, thanh hung
hieu lang » chieu sang, nhieu tang, hieu van
nong cong » cong cong, tong cong, nang cong
ban nhung » san nhung, ban phuong, gian nhung
dung cua » dung luan, dung cho
cua nong » cua cong, cuu nong, cua dong
cong ban » cong bang, cong san, cong tan

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) or (hieu quang)) - thanh dung cua nong cong ban nhung bai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu lang) OR (hieu quang)) - thanh dung cua nong cong ban nhung bai*.