Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
ve cac » va cac, vien cac
xuc va » tuc va, luc va, xac va
vi cuu » vi luu, vinh cuu

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

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