Perhaps you should try some spelling variations:
voi nang » voi hang, hoi nang, voi rang
ban hang » ngan hang
cham luc » cham soc, nhan luc, cham cuu
te sach » toc sach
hang di » hang doi, hang vi, hang dien
luc ban » duc ban, cuc ban, luc bat
va cham » va chat, va tham
hieu va » lieu va, hieu qua
vu nang » vuc nang, va nang, vu dang
cua tre » cua te, cuu tre, cua triet
di cua » dai cua, doi cua, de cua
o hai » co hai, so hai, o lai

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 ((voi nang) or (vu nang)) ((o hai) or (x ho)). hieu va cham luc ban hang di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((voi nang) OR (vu nang)) ((o hai) OR (x ho)). hieu va cham luc ban hang di cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach ((voi nang) or (vu nang)) ((o hai) or (x ho)). hieu va cham luc ban hang di cua tre*.