Perhaps you should try some spelling variations:
thien van » thi van
thanh dan » thanh san, thanh van, thanh dat
thu sach » tu sach, thuat sach, thuoc sach
dan cua » dan ca, ban cua, dai cua
van cam » van nam, van lam, van cau
ty hang » ly hang, ty xang, thi hang
ty lang » tay lang, ty xang, tu lang
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, truc va, duc va

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 ((ty lang) OR (ty hang)) xa hoi. thien van cam ((tuc va) or (tuc xa)) thanh dan cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ty lang) OR (ty hang)) xa hoi. thien van cam ((tuc va) OR (tuc xa)) thanh dan cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ty lang) OR (ty hang)) xa hoi. thien van cam ((tuc va) or (tuc xa)) thanh dan cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ty lang) OR (ty hang)) xa hoi. thien van cam ((tuc va) or (tuc xa)) thanh dan cua tre*.