Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, dien sach
chua xang » chua nang, chuc nang, chu bang
xang cong » dang cong, bang cong, hang cong
doc hieu » toc thieu, hoc thieu, hoc hien
anh dang » anh dong, anh dung, anh bang
cong anh » cong danh, dong anh, hong anh
anh van » anh va, thanh van, doanh van

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu sach - ((canh tranh) or (anh dang)) chua xang cong anh van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - ((canh tranh) OR (anh dang)) chua xang cong anh van ban.
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - ((canh tranh) or (anh dang)) chua xang cong anh van ban*.