Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
danh vai » danh sai, danh va, doanh van
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
nang ro » nang co, nang ho, nang ra
thuc va » thuc vat, thuc dan, thuc day
va danh » va dinh, va dan, va hanh
nang o » nang co, nang ho, nang x
qua am » quan am, qua ap, cua am

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