Perhaps you should try some spelling variations:
ban thanh » ban hang
ban hanh » ban hang
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac duc » cao duc, cac dac, cac nuoc
vai cua » dai cua, hai cua, lai cua
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 xa hoi. hieu va ((cac duc) or (cac du)) ((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 xa hoi. hieu va ((cac duc) OR (cac du)) ((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 xa hoi. hieu va ((cac duc) or (cac du)) ((ban thanh) OR (ban hanh)) vai cua tre*".