Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trinh » canh tranh, hanh chinh
hoc chiet » hoc thiet, hoc nhiet, hoc hien
cong sang » cong lang, cong vang, cong bang
trinh va » trinh van, trinh vat, trinh ve
cong san » cong tac
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 chiet tach - hanh trinh va hang ((cong san) or (cong sang)) phan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - hanh trinh va hang ((cong san) OR (cong sang)) phan tap.
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - hanh trinh va hang ((cong san) or (cong sang)) phan tap*.