Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vat dinh » va dinh, van dinh, vat sinh
dinh dai » dinh dat, sinh dai, dinh dao
su triet » su viet, su tien, ve triet
sach ky » sac ky, sach ty, sach kem
hieu ve » hieu va
dai su » dai sua, dai so, dan su
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 ((sach ky) OR (sach y)) nang x hoi. ((hieu ve) or (hieu van)) am thuc vat dinh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach y)) nang x hoi. ((hieu ve) OR (hieu van)) am thuc vat dinh dai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach y)) nang x hoi. ((hieu ve) or (hieu van)) am thuc vat dinh dai su triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach y)) nang x hoi. ((hieu ve) or (hieu van)) am thuc vat dinh dai su triet*.