Perhaps you should try some spelling variations:
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
cong ngang » cong nhan, cong quang, cong lang
hanh hang » thanh hang, hang hang, hanh han
cua nhung » va nhung
cong vang » cong lang, cong quang, cong san
hang cua » mang cua, hang ca, huong cua
toan cao » toan ban, toan tap

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 (thien hach)) - hanh hang cua nhung ((cong vang) OR (cong ngang)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (thien hach)) - hanh hang cua nhung ((cong vang) OR (cong ngang)) toan cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (thien hach)) - hanh hang cua nhung ((cong vang) OR (cong ngang)) toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (thien hach)) - hanh hang cua nhung ((cong vang) OR (cong ngang)) toan cao*.