Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
do trung » bo truong, le trung
trung va » truong va, trang va, trung ha
ky lang » ky nang, ky tang, tay lang
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
van do » van dao, van de, ban do
va dan » ca dan, va dao, va dau
dan di » danh di, dan da, dan de
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ky lang) or (ky dang)) xa hoi. thien van do trung va dan di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky lang) OR (ky dang)) xa hoi. thien van do trung va dan di cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky lang) or (ky dang)) xa hoi. thien van do trung va dan di cua tre*.