Perhaps you should try some spelling variations:
ban thanh » ban hang
cham duc » pham duc, cham soc, pham duy
ban hanh » ban hang
vu sach » vu bach, su sach, vu khach
vai cua » dai cua, hai cua, lai cua
va cham » va chat, va tham
hieu va » lieu va, hieu qua
ty hang » ly hang, ty xang, thi hang
ty nang » ky nang, ty xang, ly nang
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: vu sach ((ty nang) OR (ty hang)) xa hoi. hieu va cham duc ((ban thanh) or (ban hanh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ((ty nang) OR (ty hang)) xa hoi. hieu va cham duc ((ban thanh) OR (ban hanh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ((ty nang) OR (ty hang)) xa hoi. hieu va cham duc ((ban thanh) or (ban hanh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ((ty nang) OR (ty hang)) xa hoi. hieu va cham duc ((ban thanh) or (ban hanh)) vai cua tre*.