Perhaps you should try some spelling variations:
ban thanh » ban hang
hieu van » hieu va, thien van, lieu va
ban hanh » ban hang
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
y nang » ky nang, ly nang, v nang

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 y nang xa hoi. hieu van cam duc ((ban thanh) or (ban hanh)) vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. hieu van cam duc ((ban thanh) OR (ban hanh)) vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. hieu van cam duc ((ban thanh) or (ban hanh)) vi ((cua tre) or (cuu tre))*.