Perhaps you should try some spelling variations:
thien hach » thien thanh, hien hanh
chieu sach » chinh sach, chiet tach, chieu sang
hanh trinh » canh tranh, hanh chinh
trinh quan » tinh quang, trinh luat, trinh han
quan nhung » qua nhung, cua nhung, luan chung
nhung cong » dung cong, thong cong, hang cong
san toan » van toan, manh toan, xuan toan
dan toan » van toan, dan than, manh toan

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc ((thien hach) or (chieu sach)) - hanh trinh quan nhung cong ((san toan) OR (dan toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((thien hach) OR (chieu sach)) - hanh trinh quan nhung cong ((san toan) OR (dan toan)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((thien hach) or (chieu sach)) - hanh trinh quan nhung cong ((san toan) OR (dan toan)) ban".
• Adding a wildcard symbol may retrieve word variants: toc ((thien hach) or (chieu sach)) - hanh trinh quan nhung cong ((san toan) OR (dan toan)) ban*.