Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
tru nang » tra nang, tri nang, truc nano
hieu van » hieu va, thien van, lieu va
hanh va » hang va, hanh vi
danh va » doanh va, anh va, dan va
van cao » van dao, van bao, van hao
cao duc » dao duc, cao suc, giao duc
nang xa » nang x, lang xa, nang ma
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: ((te sach) OR (toc sach)) tru nang xa hoi. hieu van cao duc va ((danh va) or (hanh va)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) tru nang xa hoi. hieu van cao duc va ((danh va) OR (hanh va)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) tru nang xa hoi. hieu van cao duc va ((danh va) or (hanh va)) cua te".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) tru nang xa hoi. hieu van cao duc va ((danh va) or (hanh va)) cua te*.