Perhaps you should try some spelling variations:
trung tuan » trung thanh, trung tam, truong thanh
thong cong » trong cong, tong cong, thong thong
kien sach » dien sach, vien bach, kien mac
tran tuan » tran xuan, tran quang, tran thanh
hoc kien » hoc hien, hoc vien, hoa kien
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: hoc kien sach - manh ((trung tuan) or (tran tuan)) thong cong dan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc kien sach - manh ((trung tuan) OR (tran tuan)) thong cong dan van ban.
• Adding a wildcard symbol may retrieve word variants: hoc kien sach - manh ((trung tuan) or (tran tuan)) thong cong dan van ban*.