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
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, nang ma
dao duc » giao duc, tao duoc
va dan » ca dan, va dao, va dau
dan va » doan va, dan ca, ban va
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: ((tu sach) or (toc sach)) tru nang xa hoi. hieu van dao duc va dan va cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (toc sach)) tru nang xa hoi. hieu van dao duc va dan va cua te.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (toc sach)) tru nang xa hoi. hieu van dao duc va dan va cua te*.