Perhaps you should try some spelling variations:
cdien sach » chieu sach, kien sach
dien sach » dien anh
nhan tang » nhan dang, nham tang, nhan lang
tang luan » dung luan
van thong » van thuong, van phong, va thong
thong van » trong van, thong va, thong quan
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 ((dien sach) or (cdien sach)) - nhan tang luan van thong van toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((dien sach) OR (cdien sach)) - nhan tang luan van thong van toan cao*.