Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu van » hieu va, thien van, lieu va
lang van » dang van, hoang van, giang van
van hanh » van thanh, ban hanh, van anh
tang van » dang van, hoang van, trong van
sach tay » xach tay, sach hay, sach nay
tuc van » thuc van, truc van, tuc va
cam tuc » cam xuc, cam tu, nam thuc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
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 tay ((lang van) OR (tang van)) hoi. ((hieu ve) or (hieu van)) cam tuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach tay ((lang van) OR (tang van)) hoi. ((hieu ve) OR (hieu van)) cam tuc van hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach tay ((lang van) OR (tang van)) hoi. ((hieu ve) or (hieu van)) cam tuc van hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach tay ((lang van) OR (tang van)) hoi. ((hieu ve) or (hieu van)) cam tuc van hanh vi cua tre*.