Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
danh dai » danh dau, danh di, danh sai
trang va » tran van, hang va
hieu cao » chieu cao, hieu cac, hieu ca
trung va » truong va, trung ha, trung tam
cua tre » cua te, cuu tre, cua triet
ky tang » ky nang, ky dang, kho tang
ky lang » ky nang, ky dang, tay lang
cao ha » cao kha, cao h, cao va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu cao ha ((trung va) or (trang va)) danh dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu cao ha ((trung va) OR (trang va)) danh dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu cao ha ((trung va) or (trang va)) danh dai cua tre".
• Adding a wildcard symbol may retrieve word variants: thuoc sach ((ky lang) OR (ky tang)) xa hoi. hieu cao ha ((trung va) or (trang va)) danh dai cua tre*.