Perhaps you should try some spelling variations:
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
tieu sach » chieu sach, dien sach, te sach
nang dua » nang du, nang quan, nang luc
dan than » dan chan, ban than, van than
than ban » thanh ban, toan ban, than man

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo tieu sach - anh ((nang dua) OR (nang suat)) ((nhung cong) or (thong cong)) dan than ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo tieu sach - anh ((nang dua) OR (nang suat)) ((nhung cong) OR (thong cong)) dan than ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo tieu sach - anh ((nang dua) OR (nang suat)) ((nhung cong) or (thong cong)) dan than ban".
• Adding a wildcard symbol may retrieve word variants: theo tieu sach - anh ((nang dua) OR (nang suat)) ((nhung cong) or (thong cong)) dan than ban*.