Perhaps you should try some spelling variations:
chieu sach » chiet tach, chieu sang, chieu xanh
doanh cua » doanh luan
tong cong » trong cong, cong cong, dung cong
manh cua » ban cua
cong van » cong vang, cong san, song van
van tan » van tuan, van ban, van tai
tan tap » toan tap, han tap, tan tat

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 ((chieu sach) OR (chinh sach)) - hanh ((manh cua) OR (doanh cua)) tong cong van tan tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sach) or (chinh sach)) - hanh ((manh cua) OR (doanh cua)) tong cong van tan tap~".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sach) or (chinh sach)) - hanh ((manh cua) OR (doanh cua)) tong cong van tan tap*.