Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
thu lang » thu bang, phu lang, tho lang
danh lai » danh sai, gianh lai, dinh lam
thu hang » thi hang, thuc hanh, thu huong
hieu van » hieu va, thien van, lieu va
truc va » thuc va, thuc vat, trung va
lai cua » dai cua, hai cua, lai chau
van cau » van dau, van hau, van chat
cua tre » cua te, cuu tre, cua triet
tuc va » thuc va, tuc xa, 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 ((thu lang) OR (thu hang)) xa hoi. hieu van cau ((tuc va) or (truc va)) danh lai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((thu lang) OR (thu hang)) xa hoi. hieu van cau ((tuc va) OR (truc va)) danh lai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((thu lang) OR (thu hang)) xa hoi. hieu van cau ((tuc va) or (truc va)) danh lai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((thu lang) OR (thu hang)) xa hoi. hieu van cau ((tuc va) or (truc va)) danh lai cua tre*.