Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
danh vai » danh sai, danh va, doanh van
vat danh » va danh, van danh, luat danh
hieu ve » hieu va, hieu van
sach ky » sach y, sach ty, sach kem
nang o » nang co, nang ho, nang ro
sac ky » cac ky, sai ky
ve am » va am
o hoi » co hoi, o hoc, o hai
thuc » thu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) OR (sac ky)) nang o hoi. hieu ve am thuc vat danh vai ((cua triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sac ky)) nang o hoi. hieu ve am thuc vat danh vai ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ky) OR (sac ky)) nang o hoi. hieu ve am thuc vat danh vai ((cua triet) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) OR (sac ky)) nang o hoi. hieu ve am thuc vat danh vai ((cua triet) or (va triet))*.