Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
truc va » thuc va, thuc vat, trung va
hieu va » lieu va, hieu qua
hieu ve » hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
cuu tre » cua tre, cau tren, cau treo
xuc va » duc va, tuc va, luc va
vi cuu » vi luu, vinh cuu

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 va)) cam ((xuc va) or (truc va)) hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang xa hoi. ((hieu ve) OR (hieu va)) cam ((xuc va) OR (truc va)) hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky lang xa hoi. ((hieu ve) OR (hieu va)) cam ((xuc va) or (truc va)) hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang xa hoi. ((hieu ve) OR (hieu va)) cam ((xuc va) or (truc va)) hanh vi cuu tre*.