Perhaps you should try some spelling variations:
van chat » cao chat
sach nay » sach hay, sach vay, sach nang
dang xay » dang van, van xay
van tham » van thanh, van tuan, van tai
sach tay » xach tay, sach hay, sach tai
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
xay hoi » xa hoi, tay hoi, cay phoi
doc va » duoc va, hoc va, duc 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: te ((sach tay) OR (sach nay)) dang xay hoi. hieu ((van chat) or (van tham)) doc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach tay) OR (sach nay)) dang xay hoi. hieu ((van chat) OR (van tham)) doc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach tay) OR (sach nay)) dang xay hoi. hieu ((van chat) or (van tham)) doc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach tay) OR (sach nay)) dang xay hoi. hieu ((van chat) or (van tham)) doc va hanh vi cua tre*.