Perhaps you should try some spelling variations:
lang van » dang van, tang van, hoang van
cam thuc » am thuc, nam thuc, cam thu
thuc van » thuc vat, thuc dan, thuc va
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
va cam » va cham, va cac, va cao
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((xang xa) OR (lang van)) hoi. hieu va cam thuc van hanh vi cua tre~.
• Adding a wildcard symbol may retrieve word variants: te sach ty ((xang xa) or (lang van)) hoi. hieu va cam thuc van hanh vi cua tre*.