Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
trinh luan » trinh quan, trinh han, trinh toan
hieu cach » hieu cac, chieu sach, hieu ca
bang song » nang song
song dan » song danh, song van, cong dan
dan toan » van toan, dan than, 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: hoc ((thieu sach) OR (hieu cach)) - hanh ((trinh luan) or (trinh luat)) bang song dan toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cach)) - hanh ((trinh luan) OR (trinh luat)) bang song dan toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) OR (hieu cach)) - hanh ((trinh luan) or (trinh luat)) bang song dan toan ban".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) OR (hieu cach)) - hanh ((trinh luan) or (trinh luat)) bang song dan toan ban*.