Perhaps you should try some spelling variations:
ve triet » va trien, su triet
tai khoi » tai khoa, mai khoi, tao khoi
van hanh » van thanh, ban hanh, van anh
tu sach » thu sach, su sach, te sach
xuc van » duc van, luc van, vuc van
hanh ki » hanh vi, hanh ky, hanh kien
su viet » so viet
sach vu » sach va, sach tu, sach uu
hieu va » lieu va, hieu qua
tai hoi » dai hoi, tai hai, tai hoe
vu nang » vuc nang, va nang, vu dang
va cam » va cham, va cac, va cao

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