Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va
cao duc » dao duc, cao suc, giao duc
duc gia » quoc gia
y nang » ky nang, ly nang, v nang
ve cuu » ve cau, ve chu, ve cum
ve cua » le cua, de cua, te cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach y nang x ho. ((hieu ve) OR (hieu van)) cao duc gia thanh ((ve cuu) or (ve cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang x ho. ((hieu ve) OR (hieu van)) cao duc gia thanh ((ve cuu) OR (ve cua)) tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang x ho. ((hieu ve) OR (hieu van)) cao duc gia thanh ((ve cuu) or (ve cua)) tre*".