Perhaps you should try some spelling variations:
chiet tach » chieu sach
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
hanh nhan » thanh nhan, danh nhan, anh nhan
va thong » va thuong, va phuong, he thong
dan chan » dan gian, dan ca, van chat
dan than » ban than, van than, dan toan
nhan va » nhan tai, nhan dan, nhan tao

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chiet tach) or (hieu lang)) - hanh nhan va thong cong ((dan chan) or (dan than)) tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chiet tach) OR (hieu lang)) - hanh nhan va thong cong ((dan chan) OR (dan than)) tap.
• Adding a wildcard symbol may retrieve word variants: ho ((chiet tach) or (hieu lang)) - hanh nhan va thong cong ((dan chan) or (dan than)) tap*.