Perhaps you should try some spelling variations:
tru nang » tra nang, tri nang, thi nang
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, te sach
dao duc » giao duc, tao duoc
va danh » va dinh, va dan, va hanh
danh va » doanh va, hanh va, anh va
chua te » chua tu, chua xe, chuan ted
cua te » cua tu

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 ((tru nang) or (truc nano)) xa hoi. hieu van dao duc va danh va ((chua te) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((tru nang) OR (truc nano)) xa hoi. hieu van dao duc va danh va ((chua te) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((tru nang) or (truc nano)) xa hoi. hieu van dao duc va danh va ((chua te) OR (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach ((tru nang) or (truc nano)) xa hoi. hieu van dao duc va danh va ((chua te) OR (cua te))*.