Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
sang tao » hang tai
hieu va » lieu va, hieu qua
so sach » so sanh, bo sach, co sach
nang ma » tang ma, sang ma, nang cao
luc va » duc va, tuc va
loc va » hoc va
dai su » dai sua, dai so, dan su
va cau » van cau, va cac, va dau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y ((nang ma) or (sang tao)) hoi. hieu va cau ((luc va) OR (loc va)) hanh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((nang ma) OR (sang tao)) hoi. hieu va cau ((luc va) OR (loc va)) hanh dai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((nang ma) or (sang tao)) hoi. hieu va cau ((luc va) OR (loc va)) hanh dai su triet".
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang ma) or (sang tao)) hoi. hieu va cau ((luc va) OR (loc va)) hanh dai su triet*.