Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cao hoi » co hoi, cao hoc, tao hoi
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
va danh » va dinh, va dan, va hanh
cuu tre » cau tren, cau treo
cua tre » cua te, cua triet, dua tren
xuc va » duc va, tuc va, luc va

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