Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, nhieu tang
hanh trinh » canh tranh, hanh chinh
nhung cong » dung cong, thong cong, nhung don
hieu lang » hieu quang, nhieu tang, hieu van
trinh vat » trinh van, trinh luat, sinh vat
hang cong » dang cong, hang nong, bang cong
hach toan » thanh toan, manh toan
toan ban » van ban

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

• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sang) OR (hieu lang)) - hanh trinh vat ((nhung cong) OR (hang cong)) hach toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sang) or (hieu lang)) - hanh trinh vat ((nhung cong) OR (hang cong)) hach toan ban~".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sang) or (hieu lang)) - hanh trinh vat ((nhung cong) OR (hang cong)) hach toan ban*.