Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
ty nang » ky nang, ty xang, ty hang
lai hoi » dai hoi, lai hoa, lai roi
xuc van » duc van, luc van, vuc van
vi cua » vai cua, di cua
cua su » qua su
va cam » va cham, va cac, va cao

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 (toc sach)) ty nang ((lai hoi) or (xa hoi)). hieu va cam xuc van hanh vi cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ty nang ((lai hoi) OR (xa hoi)). hieu va cam xuc van hanh vi cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty nang ((lai hoi) or (xa hoi)). hieu va cam xuc van hanh vi cua su".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty nang ((lai hoi) or (xa hoi)). hieu va cam xuc van hanh vi cua su*.