Perhaps you should try some spelling variations:
hanh trinh » hanh chinh
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
hieu cach » hieu cac, hieu ca, biet cach
cong san » cong tac
san than » sang than, san thanh, ban than
than cau » toan cau, phan cau, 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: doc ((hieu cach) OR (chieu sach)) - ((hanh trinh) or (canh tranh)) va nhung cong san than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu cach) OR (chieu sach)) - ((hanh trinh) OR (canh tranh)) va nhung cong san than cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu cach) OR (chieu sach)) - ((hanh trinh) or (canh tranh)) va nhung cong san than cau".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu cach) OR (chieu sach)) - ((hanh trinh) or (canh tranh)) va nhung cong san than cau*.