Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
thu sach » tu sach, thuat sach, thuoc sach
thuc day » thuc dan, thuc vat
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
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: thu sach ky nang xa hoi. ((hieu ve) or (hieu qua)) cau ((thuc va) OR (thuc day)) thanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang xa hoi. ((hieu ve) OR (hieu qua)) cau ((thuc va) OR (thuc day)) thanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang xa hoi. ((hieu ve) or (hieu qua)) cau ((thuc va) OR (thuc day)) thanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang xa hoi. ((hieu ve) or (hieu qua)) cau ((thuc va) OR (thuc day)) thanh vai cua tre*.