Perhaps you should try some spelling variations:
thien thanh » tien thanh, thi thanh, hien hanh
thanh trung » thanh tung
trung thanh » truong thanh
thanh trong » tranh trong, hanh trong, nhanh trong
kien sach » dien sach, vien bach, kien mac
cong van » cong vang, cong san, song van
van khan » van khanh, van khang, van phan
khan cap » khan ap, than cap, khoan cam

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) or (thien thanh)) - thanh trung thanh trong cong van khan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((kien sach) OR (thien thanh)) - thanh trung thanh trong cong van khan cap.
• Adding a wildcard symbol may retrieve word variants: hoc ((kien sach) or (thien thanh)) - thanh trung thanh trong cong van khan cap*.