Perhaps you should try some spelling variations:
hanh dai » hanh tai, hanh dao, vanh dai
va triet » va thiet, va trien, ve triet
hieu ve » hieu va, hieu van
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
ca viet » va viet, co viet, hoa viet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai
ve am » va 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 sac ky nang o hoi. hieu ve am thuc va hanh dai ((va triet) OR (ca viet))~.
• Adding a wildcard symbol may retrieve word variants: tu sac ky nang o hoi. hieu ve am thuc va hanh dai ((va triet) or (ca viet))*.