Perhaps you should try some spelling variations:
sach tru » sach truc, sach thu, sach tren
hanh vai » hanh vi, hanh va, hanh tai
thuc day » thuc dan, thuc vat
vai cua » dai cua, hai cua, lai cua
thuc va » thuc vat, thuc dan
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach ty
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: te ((sach tru) or (sach tu)) nang xa hoi. hieu va cac ((thuc va) OR (thuc day)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tru) OR (sach tu)) nang xa hoi. hieu va cac ((thuc va) OR (thuc day)) hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tru) or (sach tu)) nang xa hoi. hieu va cac ((thuc va) OR (thuc day)) hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach tru) or (sach tu)) nang xa hoi. hieu va cac ((thuc va) OR (thuc day)) hanh vai cua tre*.