Perhaps you should try some spelling variations:
nhung chong » nhung phong, nhung phuong, phong chong
thieu sach » chieu sach, hieu cach, theo sach
thien hach » thien thanh, hien hanh
nhung cong » dung cong, thong cong, hang cong
tranh cua » doanh cua, manh cua
bai toan » bai tap
toan ban » van ban

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

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