Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
trinh luan » trinh luat, trinh quan, trinh han
hang cong » dang cong, bang cong, thanh cong
hang nong » thang long, han tong
theo chu » theo chieu, cho chu, chao chu
chu sach » cau sach, thu sach, chieu sach
san toan » van toan, dan toan, manh toan
dan than » dan chan, ban than, van than

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chu sach - hanh trinh luan ((hang cong) or (hang nong)) ((san toan) or (dan than)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chu sach - hanh trinh luan ((hang cong) OR (hang nong)) ((san toan) OR (dan than)) cao.
• Adding a wildcard symbol may retrieve word variants: theo chu sach - hanh trinh luan ((hang cong) or (hang nong)) ((san toan) or (dan than)) cao*.