Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
va hanh » van hanh, va thanh, va danh
tai cua » thai cua, tai cuc, tri cua
nam tu » nam thu, nam thuc
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: ((toc sach) or (dac sac)) ky nang x hoi. hieu van nam tu va hanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (dac sac)) ky nang x hoi. hieu van nam tu va hanh tai cua te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (dac sac)) ky nang x hoi. hieu van nam tu va hanh tai cua te*.