Perhaps you should try some spelling variations:
trinh chuan » trinh han, trinh quan, trinh luan
theo chieu » theo tieu, ho chieu, theo chu
chieu sach » chinh sach, chiet tach, chieu sang
hanh trinh » canh tranh, hanh chinh
chuan xang » chua xang, chuan trang, chua nang
xang cong » dang cong, bang cong, hang cong
dan than » dan chan, ban than, dan toan
van than » van thanh, van thang, van tuan

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo chieu sach - hanh trinh chuan xang cong ((dan than) or (van than)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo chieu sach - hanh trinh chuan xang cong ((dan than) OR (van than)) cau*.