Perhaps you should try some spelling variations:
chiet tach » chieu sach
hanh trinh » canh tranh
cua truong » cua trung, xuan truong, cac truong
hoc chiet » hoc thiet, hoc nhiet, hoc hien
cua trong » cua trung, qua trong, ca trong
cong san » cong tac
san than » sang than, san thanh, ban than
than ban » thanh ban, toan ban, than man

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chiet tach - ((hanh trinh) OR (hanh chinh)) ((cua trong) OR (cua truong)) cong san than ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc chiet tach - ((hanh trinh) OR (hanh chinh)) ((cua trong) or (cua truong)) cong san than ban~".
• Adding a wildcard symbol may retrieve word variants: hoc chiet tach - ((hanh trinh) OR (hanh chinh)) ((cua trong) or (cua truong)) cong san than ban*.