Perhaps you should try some spelling variations:
ban hang » ngan hang
su sach » so sach, vu sach
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
qua cam » qua cham, qua cac, qua ca
van anh » van thanh, tuan anh, van minh
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: su sach ((ky tang) OR (ky dang)) xa hoi. hieu qua cam xuc ((ban hang) or (van anh)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky tang) OR (ky dang)) xa hoi. hieu qua cam xuc ((ban hang) OR (van anh)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky tang) OR (ky dang)) xa hoi. hieu qua cam xuc ((ban hang) or (van anh)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky tang) OR (ky dang)) xa hoi. hieu qua cam xuc ((ban hang) or (van anh)) vai cua tre*.