Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
o hoi » co hoi, o hoc, o hai
x hoi » xa hoi, x ho, 5 hoi
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 sach ky nang ((x hoi) OR (o hoi)). hieu ve am thuc va hanh vai ((cua triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (o hoi)). hieu ve am thuc va hanh vai ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) OR (o hoi)). hieu ve am thuc va hanh vai ((cua triet) or (va triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang ((x hoi) OR (o hoi)). hieu ve am thuc va hanh vai ((cua triet) or (va triet))*.