Perhaps you should try some spelling variations:
thieu sach » thien hach, hieu cach, theo sach
chieu sach » chinh sach, chiet tach, chieu sang
nhung cong » dung cong, thong cong, hang cong
tranh cua » doanh cua, manh cua
cua nhung » va nhung
trinh cai » trinh tai, trinh cau, trinh cac
tinh cai » tinh hai, tinh cao, tinh ca

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 (chieu sach)) - canh tranh cua nhung cong ((tinh cai) OR (trinh cai)) tu~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) OR (chieu sach)) - canh tranh cua nhung cong ((tinh cai) or (trinh cai)) tu~".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) OR (chieu sach)) - canh tranh cua nhung cong ((tinh cai) or (trinh cai)) tu*.