Perhaps you should try some spelling variations:
thuc day » thuc dan, thuc vat
dinh vai » dinh van, dinh vi, dinh va
cua viet » ca viet, hoa viet, cua dieu
tu sach » thu sach, su sach, te sach
thuc va » thuc vat, thuc dan
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
qua am » quan am, qua ap, cua am
o hoi » co hoi, o hoc, o hai

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 sach y nang o hoi. hieu qua am ((thuc va) OR (thuc day)) dinh vai ((cua viet) OR (cua vat))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang o hoi. hieu qua am ((thuc va) or (thuc day)) dinh vai ((cua viet) OR (cua vat))~".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hoi. hieu qua am ((thuc va) or (thuc day)) dinh vai ((cua viet) OR (cua vat))*.