Perhaps you should try some spelling variations:
vanh dai » van dai, vanh tai, lanh dao
tu sach » thu sach, su sach, te sach
cam tuc » cam xuc, cam tu, nam thuc
cuu tre » cau tren, cau treo
va vanh » va van, va danh, va hanh
cua tre » cua te, cua triet, dua tren
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
tuc va » thuc va, truc va, tuc xa
s_ hai » su hai, so hai
va cam » va cham, va cac, va cao

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 ty nang ((_ hai) OR (s_ hai)). hieu va cam tuc va vanh dai ((cuu tre) OR (cua tre))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang ((_ hai) or (s_ hai)). hieu va cam tuc va vanh dai ((cuu tre) OR (cua tre))~".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((_ hai) or (s_ hai)). hieu va cam tuc va vanh dai ((cuu tre) OR (cua tre))*.