Perhaps you should try some spelling variations:
ban thanh » ban hanh
ban hang » ngan hang
su sach » so sach, vu sach
ly vang » ly hang, ly van, ly quang
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
lai cuu » lai cua, lai chau, lai cuoc
cuu tre » cua tre, cau tren, cau treo

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 ((ly vang) or (ky nang)) xa hoi. hieu va cac duc ((ban thanh) OR (ban hang)) lai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ly vang) OR (ky nang)) xa hoi. hieu va cac duc ((ban thanh) OR (ban hang)) lai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ly vang) or (ky nang)) xa hoi. hieu va cac duc ((ban thanh) OR (ban hang)) lai cuu tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ly vang) or (ky nang)) xa hoi. hieu va cac duc ((ban thanh) OR (ban hang)) lai cuu tre*.