Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, mang may
hieu va » lieu va, hieu qua
cac xuc » cam xuc, cac nuoc, chat xuc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, tuc va, luc va
cua tu » cua tuc, cua su, cua cu

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 y ((nang ma) OR (nang cao)) hoi. hieu va cac xuc va hanh vi ((cua tre) OR (cua tu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang ma) OR (nang cao)) hoi. hieu va cac xuc va hanh vi ((cua tre) or (cua tu))~".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ma) OR (nang cao)) hoi. hieu va cac xuc va hanh vi ((cua tre) or (cua tu))*.