Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
hoc sach » hoc sinh, hoc cac, hoc anh
nha nang » nham nang, kha nang, nha hang
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
truc va » thuc va, trung va
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach nha nang xa hoi. ((hieu va) OR (lieu va)) cam ((truc va) or (thuc vat)) thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach nha nang xa hoi. ((hieu va) OR (lieu va)) cam ((truc va) OR (thuc vat)) thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach nha nang xa hoi. ((hieu va) OR (lieu va)) cam ((truc va) or (thuc vat)) thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc sach nha nang xa hoi. ((hieu va) OR (lieu va)) cam ((truc va) or (thuc vat)) thanh vai cua tre*.