Perhaps you should try some spelling variations:
thanh duong » thanh huong, thanh cuong, thanh vuong
chieu sach » chinh sach, chieu sang, chieu xanh
thanh hung » thanh huong, thanh tung, thanh trung
nhung cong » dung cong, thong cong, hang cong
cong tan » cong tac, cong san, cong thanh
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: theo ((chieu sach) OR (chiet tach)) - ((thanh hung) or (thanh duong)) va nhung cong tan tran tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chiet tach)) - ((thanh hung) OR (thanh duong)) va nhung cong tan tran tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) OR (chiet tach)) - ((thanh hung) or (thanh duong)) va nhung cong tan tran tap".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) OR (chiet tach)) - ((thanh hung) or (thanh duong)) va nhung cong tan tran tap*.