Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su triet » su viet, su tien, 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
va dinh » van dinh, va kinh, va tinh
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 dinh van ((su 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 dinh van ((su triet) OR (cua vat))*.