Perhaps you should try some spelling variations:
duc danh » duc anh, duc hanh, duc dan
duc manh » suc manh, duc anh, duc minh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
hai dat » hoi dat, hai dan, chap dat
x hoi » xa hoi, o hoi, x ho

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 ky nang x hoi. hieu vu cham ((duc danh) OR (duc manh)) thanh ((hai dat) OR (cai dat)) tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x hoi. hieu vu cham ((duc danh) or (duc manh)) thanh ((hai dat) OR (cai dat)) tren~".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu vu cham ((duc danh) or (duc manh)) thanh ((hai dat) OR (cai dat)) tren*.