Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh tai, hanh van
va triet » va thiet, va trien, ve triet
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
thuc va » thuc vat, thuc dan, thuc day
hanh va » hang va, hanh vi
van am » van nam, van lam, van dam
x hoi » xa hoi, o hoi, x ho

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. hieu van am thuc va ((hanh vai) or (hanh va)) ((va triet) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x hoi. hieu van am thuc va ((hanh vai) OR (hanh va)) ((va triet) OR (cua vat)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x hoi. hieu van am thuc va ((hanh vai) or (hanh va)) ((va triet) or (cua vat))*.