Perhaps you should try some spelling variations:
ban hanh » ban hang
hanh tai » thanh tai, hang tai, han tai
hieu va » lieu va, hieu qua
cam duc » cam xuc, cao duc, pham duc
duc ban » duc tan, duc van, dua ban
tai cua » thai cua, tai cuc, tri cua
san ky » sang ky, dan ky, ban ky
co hai » co dai, co hoi, o hai
va cam » va cham, va cac, va cao
cua cu » cua chu, cua cau, cua su
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((san ky) OR (van ky)) nang ((x hoi) or (co hai)). hieu va cam duc ban hanh tai cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((san ky) OR (van ky)) nang ((x hoi) OR (co hai)). hieu va cam duc ban hanh tai cua cu*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((san ky) OR (van ky)) nang ((x hoi) or (co hai)). hieu va cam duc ban hanh tai cua cu*".