Perhaps you should try some spelling variations:
trung tuan » trung thanh, trung tam, tran tuan
nhung cong » dung cong, thong cong, hang cong
dien sach » dien anh
trung cua » truong cua, trung cap, dung cua
doc dien » duoc dien, doi dien, do dien
cong dan » cong san, cong tan, huong dan
dan van » dang van, doan van, dao 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 dien sach - manh ((trung cua) or (trung tuan)) nhung cong dan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc dien sach - manh ((trung cua) OR (trung tuan)) nhung cong dan van ban.
• Adding a wildcard symbol may retrieve word variants: doc dien sach - manh ((trung cua) or (trung tuan)) nhung cong dan van ban*.