Perhaps you should try some spelling variations:
thieu sach » thien hach, hieu cach, theo sach
chieu sach » chinh sach, chiet tach, chieu sang
trinh quan » tinh quang, trinh luat, trinh han
trinh cua » tinh cua, trinh luat, trinh luan
dung cong » dung trong
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.

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