Perhaps you should try some spelling variations:
va hanh » van hanh, va thanh, va danh
hai chu » hai chau, hoi chu, hai chi
hai cau » hai chau, hai hau, hoi cau
tu sach » thu sach, su sach, te sach
cao hoi » cau hoi, cao hoc, tao hoi
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
tuc va » thuc va, truc va, tuc xa
co hoi » co hoc, co loi

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y nang ((cao hoi) or (co hoi)). hieu ve cac tuc va hanh ((hai cau) or (hai chu)) treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang ((cao hoi) OR (co hoi)). hieu ve cac tuc va hanh ((hai cau) OR (hai chu)) treo.
• Adding a wildcard symbol may retrieve word variants: tu sach y nang ((cao hoi) or (co hoi)). hieu ve cac tuc va hanh ((hai cau) or (hai chu)) treo*.