Perhaps you should try some spelling variations:
ban hang » ngan hang
vuc nang » cuc nang, vu nang, chuc nang
te sach » toc sach
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
luc ban » duc ban, cuc ban, luc bat
hang di » hang doi, hang vi, hang dien
cua tre » cua te, cuu tre, cua triet
v nang » va nang, vu nang, van nang
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, o hoi, 5 hoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((v nang) or (vuc nang)) ((x hoi) or (x ho)). hieu va cac luc ban hang di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((v nang) OR (vuc nang)) ((x hoi) OR (x ho)). hieu va cac luc ban hang di cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ((v nang) or (vuc nang)) ((x hoi) or (x ho)). hieu va cac luc ban hang di cua tre*.