Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
sach vu » sach va, sach tu, sach uu
hanh ki » hanh ky, hanh kien, thanh kim
xuc van » duc van, luc van, vuc van
va cham » va chat, va tham
cao hoi » cau hoi, co hoi, cao hoc
vu nang » vuc nang, va nang, vu dang
su viet » so viet
va cam » va cac, va cao, va cai

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 vu nang cao hoi. hieu ((va cam) OR (va cham)) xuc van ((hanh ki) or (hanh vi)) su viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach vu nang cao hoi. hieu ((va cam) OR (va cham)) xuc van ((hanh ki) OR (hanh vi)) su viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach vu nang cao hoi. hieu ((va cam) OR (va cham)) xuc van ((hanh ki) or (hanh vi)) su viet".
• Adding a wildcard symbol may retrieve word variants: tu sach vu nang cao hoi. hieu ((va cam) OR (va cham)) xuc van ((hanh ki) or (hanh vi)) su viet*.