Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
hieu van » hieu va, thien van, lieu va
can bang » cao bang, can ban, van ban
bang kho » bang khi, bang cho, bang tho
te sach » toc sach
van tom » van tam, van toi, van toa
tom hoc » toc hoc, tam hoc, toan hoc
hoc can » hoc dan, hoc cao, hoc cac
kho cua » khoe cua, khi cua, cho cua
cua te » cua tu
x hoi » xa hoi, o hoi, x ho

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 (doc sach)) ky nang x hoi. hieu van tom hoc can bang kho cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (doc sach)) ky nang x hoi. hieu van tom hoc can bang kho cua te.
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (doc sach)) ky nang x hoi. hieu van tom hoc can bang kho cua te*.