Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
trinh quan » tinh quang, trinh luat, trinh han
thi chieu » thi chien, thi hieu, theo chieu
quan hang » quan hoang, quan lang, quan hanh
hang cong » dang cong, hang nong, bang cong
ho chieu » theo chieu, hoc thieu, doi chieu
doan van » doan va, hoang van, luan van
dan van » dang van, dao van, tan van

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

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