Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
thanh vai » thanh hai, thanh van, thanh tai
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
cac duc » cac du, cao duc, cac dac
duc ban » duc tan, duc van, dua ban
cua tre » cua te, cua triet, dua tren
cuu 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 ((ty xang) or (ky nang)) xa hoi. hieu va cac duc ban thanh vai ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ty xang) OR (ky nang)) xa hoi. hieu va cac duc ban thanh vai ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ty xang) or (ky nang)) xa hoi. hieu va cac duc ban thanh vai ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: su sach ((ty xang) or (ky nang)) xa hoi. hieu va cac duc ban thanh vai ((cua tre) OR (cuu tre))*.