Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
qua van » quan van, qua ban, qua san
cuu tre » cua tre, cau tren, cau treo
hieu ha » hieu hoa, hieu va, hieu xa
hieu ca » hieu cac, hieu cua, hieu va
qua va » quan va, vua va, qua ca
vi cuu » vi luu, vinh cuu
x hoi » xa hoi, o hoi, x ho

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