Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
nam thuc » nam thuoc, am thuc, nam thu
hang tai » hang va, dung tai
hieu van » hieu va, thien van, lieu va
tai cua » thai cua, tai cuc, tri cua
va hang » van hang, va nang, va lang
nam tuc » nam truc, nam tu, nam thuoc
nang o » nang co, nang ho, nang ro
cua te » cua tu
o hoi » co hoi, o hoc, o hai

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((toc sach) or (dac sac)) ky nang o hoi. hieu van ((nam tuc) or (nam thuc)) va hang tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (dac sac)) ky nang o hoi. hieu van ((nam tuc) OR (nam thuc)) va hang tai cua te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (dac sac)) ky nang o hoi. hieu van ((nam tuc) or (nam thuc)) va hang tai cua te*.