Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
van hanh » van thanh, ban hanh, van anh
te sach » toc sach
nang xa » lang xa, nang ma, mang xa
qua cac » cua cac
cac xuc » cam xuc, cac nuoc, chat xuc
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
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: te sach v ((nang xa) or (nang x)) hoi. hieu qua cac xuc ((va thanh) or (van hanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach v ((nang xa) OR (nang x)) hoi. hieu qua cac xuc ((va thanh) OR (van hanh)) vi cua tre.
• Adding a wildcard symbol may retrieve word variants: te sach v ((nang xa) or (nang x)) hoi. hieu qua cac xuc ((va thanh) or (van hanh)) vi cua tre*.