Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh hai » thanh hai, nhanh hai, hang hai
hieu ve » hieu va, hieu van
hai cua » thai cua, dai cua, hoi cua
y nang » ly nang, v nang, may nang
ve cac » va cac, vien cac
xac va » tac va, ac va, bac va
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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: thu sach ((y nang) OR (ky nang)) o hoi. hieu ve cac ((xac va) OR (duc va)) hanh hai cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((y nang) OR (ky nang)) o hoi. hieu ve cac ((xac va) or (duc va)) hanh hai cua te~".
• Adding a wildcard symbol may retrieve word variants: thu sach ((y nang) OR (ky nang)) o hoi. hieu ve cac ((xac va) or (duc va)) hanh hai cua te*.