Perhaps you should try some spelling variations:
khien tinh » thien tinh, khien thich, bien tinh
hanh trinh » canh tranh, hanh chinh
quan trong » gian trong
hien tinh » thien tinh, bien tinh, dien tinh
quan tong » quan dong, quan long, quan nong
cong san » cong tac
san toan » van toan, dan toan, manh toan
toan ban » van ban

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 ((hien tinh) OR (khien tinh)) - hanh trinh ((quan tong) OR (quan trong)) cong san toan ban~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien tinh) or (khien tinh)) - hanh trinh ((quan tong) OR (quan trong)) cong san toan ban~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien tinh) or (khien tinh)) - hanh trinh ((quan tong) OR (quan trong)) cong san toan ban*.