Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
cac tuc » cac toc, cac tu, cac tac
xa dinh » xac dinh, va dinh, ba dinh
dinh ca » dinh cac, dinh cua, dinh cao
y nang » ly nang, v nang, may nang
me hoi » le hoi
ca cua » co cua
cua te » cua tu

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) OR (ky nang)) ((me hoi) OR (ma hoa)). hieu va cac tuc xa dinh ca cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) OR (ky nang)) ((me hoi) or (ma hoa)). hieu va cac tuc xa dinh ca cua te~".
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) OR (ky nang)) ((me hoi) or (ma hoa)). hieu va cac tuc xa dinh ca cua te*.