Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
tru nang » tra nang, tri nang, thi nang
hieu van » hieu va, thien van, lieu va
va hanh » van hanh, va thanh, ban hanh
va danh » va dinh, va dan, dia danh
van cao » van dao, van bao, van hao
cao duc » dao duc, cao suc, giao duc
va cua » va chua, via cua, ca cua
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: thu sach ((tru nang) OR (truc nano)) xa hoi. hieu van cao duc ((va danh) or (va hanh)) va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((tru nang) OR (truc nano)) xa hoi. hieu van cao duc ((va danh) OR (va hanh)) va cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((tru nang) OR (truc nano)) xa hoi. hieu van cao duc ((va danh) or (va hanh)) va cua te".
• Adding a wildcard symbol may retrieve word variants: thu sach ((tru nang) OR (truc nano)) xa hoi. hieu van cao duc ((va danh) or (va hanh)) va cua te*.