Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
chieu xanh » chieu sang, chieu tinh, hieu manh
hanh trinh » canh tranh, hanh chinh
trinh tuan » trinh quan, trinh toan, trinh luan
nhung cong » dung cong, hang cong, nhung don
thong cong » trong cong, tong cong, thong thong
tan van » tran van, tang van, luan van

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sach) or (chieu xanh)) - hanh trinh tuan ((nhung cong) OR (thong cong)) tan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sach) OR (chieu xanh)) - hanh trinh tuan ((nhung cong) OR (thong cong)) tan van ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) or (chieu xanh)) - hanh trinh tuan ((nhung cong) OR (thong cong)) tan van ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (chieu xanh)) - hanh trinh tuan ((nhung cong) OR (thong cong)) tan van ban*.