Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
tay lang » tai lang, tay tang, tay quang
ban hanh » ban hang
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
tuc ban » thuc ban, truc ban, tu ban
cam tuc » cam xuc, cam tu, nam thuc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
van hoi » van hoa, van hoc, van hoe
y lang » o lang, _ lang, yen lang

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 (tay lang)) van hoi. ((hieu ve) or (hieu va)) cam tuc ban hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y lang) OR (tay lang)) van hoi. ((hieu ve) OR (hieu va)) cam tuc ban hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: toc sach ((y lang) or (tay lang)) van hoi. ((hieu ve) or (hieu va)) cam tuc ban hanh vai cua tre*.