Perhaps you should try some spelling variations:
hanh hanh » hanh han, xanh hanh, nhanh thanh
cua viet » ca viet, hoa viet, cua vat
hieu van » hieu va, thien van, lieu va
hanh lai » hanh lam, hanh tai, thanh lap
duc hanh » duc thanh, duc anh, du hanh
cham duc » pham duc, cham soc, pham duy
van cham » van chat, van tham, va cham
ty nang » ty xang, ty hang, ly nang
lai cua » dai cua, hai cua, lai chau
tu sach » thu sach, su sach, te sach
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 sach ((ty nang) or (ky nang)) ((x hoi) or (o hoi)). hieu van cham duc hanh hanh lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ty nang) OR (ky nang)) ((x hoi) OR (o hoi)). hieu van cham duc hanh hanh lai cua viet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ty nang) or (ky nang)) ((x hoi) or (o hoi)). hieu van cham duc hanh hanh lai cua viet*.