Perhaps you should try some spelling variations:
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
cua tre » cua te, cuu tre, cua triet
hanh ve » hanh vi, hanh va, hanh kem
mai hoi » mai khoi, dai hoi, lai hoi
ve cua » le cua, de cua, te cua
tu cai » tu cac, tu can, tu bai
cai ky » cao ky, cac ky, cam ky
ma hoi » xa hoi, ma hoa, me hoi
le nam » ly nam, he nam, te nam
le na » le va, le ta, le ha

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

• If you are trying to use Boolean operators, they must be ALL CAPS: tu cai ky nang ((ma hoi) OR (mai hoi)). hieu ((le nam) OR (le na)) thuc day hanh ve cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu cai ky nang ((ma hoi) or (mai hoi)). hieu ((le nam) OR (le na)) thuc day hanh ve cua tre~".
• Adding a wildcard symbol may retrieve word variants: tu cai ky nang ((ma hoi) or (mai hoi)). hieu ((le nam) OR (le na)) thuc day hanh ve cua tre*.