Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
su sach » so sach
cac duc » cac du, cao duc, cac dac
vai cua » dai cua, hai cua, lai cua
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
ty nang » ky nang, ty xang, ty hang
vu sach » vu bach, vu khach
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((su sach) OR (vu sach)) ty nang xa hoi. hieu va cac duc ((ban thanh) or (ngan hang)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ty nang xa hoi. hieu va cac duc ((ban thanh) OR (ngan hang)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) ty nang xa hoi. hieu va cac duc ((ban thanh) or (ngan hang)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) ty nang xa hoi. hieu va cac duc ((ban thanh) or (ngan hang)) vai cua tre*.