Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vat dinh » va dinh, van dinh, vat sinh
dinh vai » dinh van, dinh vi, dinh va
su triet » su tien, ve triet
su viet » so viet
tu sac » tu sach, tu cac, tu san
sac ky » cac ky, sai ky
van am » van nam, van lam, van dam
x hoi » xa hoi, o hoi, x ho
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: tu sac ky nang x hoi. hieu van am thuc vat dinh vai ((((su triet) OR (su viet))) or (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sac ky nang x hoi. hieu van am thuc vat dinh vai ((((su triet) OR (su viet))) OR (cua vat))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sac ky nang x hoi. hieu van am thuc vat dinh vai ((((su triet) OR (su viet))) or (cua vat))*".