Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, dien sach
manh tung » manh hung, thanh tung
cap thang » cau thang, cang thang, nam thang
doc hieu » toc thieu, hoc thieu, hoc hien
long van » luong van, song van, lang van
van toan » van tuan, van tan, van thanh
toan cao » toan ban, toan tap

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 - manh tung ((cap thang) or (tai trung)) long van toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - manh tung ((cap thang) OR (tai trung)) long van toan cao.
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - manh tung ((cap thang) or (tai trung)) long van toan cao*.