Perhaps you should try some spelling variations:
chiet tach » chieu sach
thanh tung » thanh cong
thong cong » trong cong, tong cong, thong thong
hieu lang » chieu sang, hieu quang, nhieu tang
vap thong » va thong, van thong, phap thong
tung vap » tung va, trung van, tuong vao
cong tan » cong tac, cong san, cong thanh
phan dau » phan tu, hang dau
han dau » hang dau, van dau, ban dau

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)) - thanh tung vap thong cong tan ((han dau) OR (phan dau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chiet tach) OR (hieu lang)) - thanh tung vap thong cong tan ((han dau) OR (phan dau))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chiet tach) or (hieu lang)) - thanh tung vap thong cong tan ((han dau) OR (phan dau))*".