Perhaps you should try some spelling variations:
hanh tai » thanh tai, hang tai, han tai
ban hanh » ban hang
hieu va » lieu va, hieu qua
tai cua » thai cua, tai cuc, tri cua
duc ban » duc tan, duc van, dua ban
hieu ve » hieu van
cam duc » cam xuc, cao duc, pham duc
tu sac » tu sach, tu cac, tu san
cua cu » cua chu, cua cau, cua su
sac ky » cac ky, sai ky
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 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: tu sac ky nang ((x hoi) or (o hoi)). ((hieu ve) OR (hieu va)) cam duc ban hanh tai cua cu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((x hoi) OR (o hoi)). ((hieu ve) OR (hieu va)) cam duc ban hanh tai cua cu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((x hoi) or (o hoi)). ((hieu ve) OR (hieu va)) cam duc ban hanh tai cua cu".
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((x hoi) or (o hoi)). ((hieu ve) OR (hieu va)) cam duc ban hanh tai cua cu*.