Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
van hanh » van thanh, ban hanh, van anh
tay lang » tai lang, tay tang, tay quang
va chat » van chat, va phat, cao chat
tuc van » thuc van, truc van, tuc va
ve chat » van chat
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, yen lang
vi cua » vai cua, di 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 (tay lang)) van hoa. hieu ((ve chat) or (va chat)) tuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ((y lang) OR (tay lang)) van hoa. hieu ((ve chat) OR (va chat)) tuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ((y lang) OR (tay lang)) van hoa. hieu ((ve chat) or (va chat)) tuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ((y lang) OR (tay lang)) van hoa. hieu ((ve chat) or (va chat)) tuc van hanh vi cua tre*.