Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
cua triet » cua viet, su triet, va triet
vu khach » vu khanh, vu khac, vay khach
thuc day » thuc dan, thuc vat
thanh vi » hanh vi, thanh va, thanh ve
cua tre » cua te, cuu tre, dua tren
y nang » ky nang, ly nang, v nang
ve nam » va nam, le nam, te nam
he nam » ha nam, nghe nam
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: vu khach y nang x hoi. hieu ((ve nam) OR (he nam)) thuc day thanh vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu khach y nang x hoi. hieu ((ve nam) OR (he nam)) thuc day thanh vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu khach y nang x hoi. hieu ((ve nam) OR (he nam)) thuc day thanh vi ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: vu khach y nang x hoi. hieu ((ve nam) OR (he nam)) thuc day thanh vi ((cua tre) or (cua triet))*.