Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
van hanh » van thanh, ban hanh, van anh
thai cua » than cua, tai cuc, tri cua
doc sach » hoc sach, nuoc sach, dac sac
nang co » nang cao, nang doc, nang noi
tai cua » tai cuc, tri cua, dai cua
hieu va » lieu va, hieu qua
cao xuc » cam xuc, cao duc, cao suc
xuc van » duc van, luc van, vuc van
va cao » va cac, va co, va dao
co hoi » co hoc, co loi
y nang » ky nang, ly nang, v nang

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