Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
hieu va » lieu va, hieu qua
cao xuc » cam xuc, cao duc, cao suc
xuc ban » duc ban, cuc ban, quoc ban
tai cua » thai cua, tri cua, dai cua
y nang » ly nang, v nang, may nang
co hoi » co hoc, co loi
va cao » va cac, va co, va dao

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 ((y nang) or (ky nang)) co hoi. hieu va cao xuc ban hanh ((tai cua) OR (tai cuc)) te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y nang) OR (ky nang)) co hoi. hieu va cao xuc ban hanh ((tai cua) OR (tai cuc)) te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y nang) or (ky nang)) co hoi. hieu va cao xuc ban hanh ((tai cua) OR (tai cuc)) te".
• Adding a wildcard symbol may retrieve word variants: toc sach ((y nang) or (ky nang)) co hoi. hieu va cao xuc ban hanh ((tai cua) OR (tai cuc)) te*.