Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tan dinh » tran dinh, van dinh, tai dinh
thi cuc » tai cuc
thi cua » thai cua, tri cua, thi dua
cao duc » dao duc, cao suc, giao duc
tu sach » thu sach, su sach, te sach
hieu ve » hieu va
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
o hai » co hai, so hai, o lai

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 y nang o hai. ((hieu ve) or (hieu van)) cao duc tan dinh ((thi cua) OR (thi cuc)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang o hai. ((hieu ve) OR (hieu van)) cao duc tan dinh ((thi cua) OR (thi cuc)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang o hai. ((hieu ve) or (hieu van)) cao duc tan dinh ((thi cua) OR (thi cuc)) te".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang o hai. ((hieu ve) or (hieu van)) cao duc tan dinh ((thi cua) OR (thi cuc)) te*.