Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, theo sach
thanh toan » thanh hoa, thanh san, tinh toan
hieu cach » hieu cac, chieu sach, hieu ca
hang hang » nang hang, cang thang, hung thang
manh toan » anh tuan, tinh toan
va thong » va thuong, va phuong, he thong

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)) - hang hang va thong thong ((manh toan) or (thanh toan)) cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu cach)) - hang hang va thong thong ((manh toan) OR (thanh toan)) cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) OR (hieu cach)) - hang hang va thong thong ((manh toan) or (thanh toan)) cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) OR (hieu cach)) - hang hang va thong thong ((manh toan) or (thanh toan)) cau*.