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 » hieu qua
xuc van » duc van, luc van, vuc van
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
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 ((y lang) or (_ land)) xa hoi. ((hieu va) or (lieu va)) cam xuc van hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y lang) OR (_ land)) xa hoi. ((hieu va) OR (lieu va)) cam xuc van hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((y lang) or (_ land)) xa hoi. ((hieu va) or (lieu va)) cam xuc van hanh va cua tre*.