Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu xanh
chieu sang » chieu xanh, hieu lang, nhieu tang
hanh trinh » canh tranh, hanh chinh
cong bang » cuong bang, dong bang, hong bang
trinh va » trinh van, trinh vat, trinh ve
cong ban » cong san, cong tan, cong dan
phan tap » phan lap, han tap, pha tap
va hang » van hang, va nang, va lang

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