Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
chieu sach » chinh sach, chiet tach, chieu sang
hieu manh » chieu xanh, hieu nganh, dieu hanh
trinh va » trinh van, trinh vat, trinh ve
dung ung » dung cong
dan toan » van toan, manh toan, xuan toan
dan than » dan chan, ban than, van than
va dung » van dung, va duong, vat dung

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((hieu manh) or (chieu sach)) - hanh trinh va dung ung ((dan toan) OR (dan than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((hieu manh) OR (chieu sach)) - hanh trinh va dung ung ((dan toan) OR (dan than)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((hieu manh) or (chieu sach)) - hanh trinh va dung ung ((dan toan) OR (dan than)) cau".
• Adding a wildcard symbol may retrieve word variants: theo ((hieu manh) or (chieu sach)) - hanh trinh va dung ung ((dan toan) OR (dan than)) cau*.