Perhaps you should try some spelling variations:
cau theo » cau thi, cau tao
hanh hai » thanh hai, nhanh hai, hang hai
hai cau » hai chau, hai chu, hai hau
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
vu sach » vu bach, su sach, vu khach
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
va cam » va cham, va cac, va cao
o hoc » co hoc, mo hoc, so hoc
o hoi » co hoi, o hai, o hoa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang ((o hoi) OR (o hoc)). hieu va cam ((xuc va) or (tuc va)) hanh hai cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ((o hoi) OR (o hoc)). hieu va cam ((xuc va) OR (tuc va)) hanh hai cau theo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang ((o hoi) OR (o hoc)). hieu va cam ((xuc va) or (tuc va)) hanh hai cau theo".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang ((o hoi) OR (o hoc)). hieu va cam ((xuc va) or (tuc va)) hanh hai cau theo*.