Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
sach ky » sac ky, sach y, sach ty
hanh va » hang va, hanh vi
xuc van » duc van, luc van, vuc van
cao xuc » cam xuc, cao duc, cao suc
hieu va » lieu va, hieu qua
dai moi » doi moi, dai hoi
mai hoi » mai khoi, dai hoi, lai hoi
mai doi » moi doi, mai khoi, mai duoc
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet
va cao » va cac, va co, va dao
va cua » va chua, via cua, ca cua

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 ky lang ((((mai hoi) or (mai doi))) or (dai moi)). hieu va cao xuc van hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang ((((mai hoi) OR (mai doi))) OR (dai moi)). hieu va cao xuc van hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang ((((mai hoi) or (mai doi))) or (dai moi)). hieu va cao xuc van hanh va cua tre*.