Perhaps you should try some spelling variations:
dinh vai » dinh van, dinh vi, dinh tai
sach thu » sach thue, sach thieu, sach tham
do thuc » hoc thuc, dan thuc
dinh va » dinh van, dinh ve, tinh va
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
sach tu » cach tu, sach ty, sach uu
hieu va » lieu va, hieu qua
x hoi » xa hoi, o hoi, x ho
va do » va dao, va doc, va co

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 tu) or (sach thu)) nang x hoi. hieu va do thuc va ((dinh vai) OR (dinh va)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tu) OR (sach thu)) nang x hoi. hieu va do thuc va ((dinh vai) OR (dinh va)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tu) or (sach thu)) nang x hoi. hieu va do thuc va ((dinh vai) OR (dinh va)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach tu) or (sach thu)) nang x hoi. hieu va do thuc va ((dinh vai) OR (dinh va)) cua tre*.