Perhaps you should try some spelling variations:
danh sai » dung sai, danh bat, danh dau
dinh lam » dinh van, tinh lao
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
cua tre » cua te, cuu tre, cua triet
cac duc » cao duc, cac dac, cac nuoc
hieu va » lieu va, hieu qua
nong xa » song xa, dong xa, nong va
tu nong » tu dong, tu cong, tu tong

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach tu nong xa hoi. hieu va ((cac duc) OR (cac du)) va ((dinh lam) or (danh sai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nong xa hoi. hieu va ((cac duc) OR (cac du)) va ((dinh lam) OR (danh sai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu nong xa hoi. hieu va ((cac duc) OR (cac du)) va ((dinh lam) or (danh sai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach tu nong xa hoi. hieu va ((cac duc) OR (cac du)) va ((dinh lam) or (danh sai)) cua tre*.