Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
nhanh tinh » nhanh thanh, hanh trinh, nhan sinh
thong cong » trong cong, tong cong, thong thong
hieu manh » chieu xanh, hieu nganh, dieu hanh
cua thong » cua thuong, cua khong, cua tong
tinh cua » trinh cua, sinh cua, tinh chat
cong tac » cong ty
tac ca » tac cua, tac can, tac cay
ca cau » cua cau, cac cau, can cau

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((hieu manh) or (chieu sach)) - nhanh tinh cua thong cong tac ca cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((hieu manh) OR (chieu sach)) - nhanh tinh cua thong cong tac ca cau.
• Adding a wildcard symbol may retrieve word variants: doi ((hieu manh) or (chieu sach)) - nhanh tinh cua thong cong tac ca cau*.