Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
hanh trinh » canh tranh, hanh chinh
thong cong » trong cong, tong cong, thong thong
hieu manh » chieu xanh, hieu nganh, dieu hanh
trinh va » trinh van, trinh vat, trinh ve
va thong » va thuong, va phuong, he thong
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cao » toan cao, thai cao, than cap

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 (hieu manh)) - hanh trinh va thong cong dan than cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (hieu manh)) - hanh trinh va thong cong dan than cao.
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (hieu manh)) - hanh trinh va thong cong dan than cao*.