Perhaps you should try some spelling variations:
thuc van » thuc vat, thuc dan, thuc va
va triet » va thiet, va trien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
van hanh » van thanh, ban hanh, van anh
ca viet » va viet, co viet, hoa viet
hieu ve » hieu va, hieu van
sac ky » cac 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.

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