Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
sach ky » sac ky, sach y, sach ty
danh vi » dinh vi, danh di, danh va
cam cua » ca cua, nam cua, cau cua
tu sach » thu sach, su sach, te sach
hieu ve » hieu va
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
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: tu sach ky lang xa hoi. ((hieu ve) or (hieu van)) cam cua ban ((danh vi) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. ((hieu ve) OR (hieu van)) cam cua ban ((danh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. ((hieu ve) or (hieu van)) cam cua ban ((danh vi) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. ((hieu ve) or (hieu van)) cam cua ban ((danh vi) OR (hanh vi)) cua tre*.