Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
ca viet » va viet, co viet, hoa viet
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hieu ve » hieu va, hieu van
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
o hai » co hai, so hai, o lai
o hoi » co hoi, o hoc, o hoa
ve am » va am

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sac ky nang ((o hoi) OR (o hai)). hieu ve am thuc va hanh dai ((va triet) or (ca viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang ((o hoi) OR (o hai)). hieu ve am thuc va hanh dai ((va triet) OR (ca viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang ((o hoi) OR (o hai)). hieu ve am thuc va hanh dai ((va triet) or (ca viet))*".