Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
thanh tung » thanh cong
hieu lang » chieu sang, hieu quang, nhieu tang
tung quan » tuong quan, trung quan, dung quan
quan dung » quang dung, quan duong, qua dung
dung cong » dung trong
nang phap » nang phat, nang phan, ban phap
bang php » bang thep, mang phap, lang phu

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 sach) or (hieu lang)) - thanh tung quan dung cong ((bang php) or (nang phap)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu sach) OR (hieu lang)) - thanh tung quan dung cong ((bang php) OR (nang phap)) cau.
• Adding a wildcard symbol may retrieve word variants: ho ((chieu sach) or (hieu lang)) - thanh tung quan dung cong ((bang php) or (nang phap)) cau*.