Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
hac tuc » thac toc, thai tuc
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
va hac » van hac, va khac, va cac
tuc va » thuc va, truc va, tuc xa
vi cau » va cau, ve cau, di cau
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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 va hac tuc va danh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((x hoi) OR (o hoi)). hieu va hac tuc va danh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang ((x hoi) or (o hoi)). hieu va hac tuc va danh vi cau tren*.