Perhaps you should try some spelling variations:
manh hai » lanh hai, minh hai, thanh hai
ban manh » ban hanh, van manh, ban mach
dang xay » dang van, van xay
quoc ban » quoc bao, quoc lan, quoc quan
hai cua » thai cua, dai cua, hoi cua
van cau » van dau, van hau, van chat
sach ty » sach tu, sach thu, xach tay
xay hoi » xa hoi, tay hoi, cay phoi
cua tre » cua te, cuu tre, cua triet

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: su ((sach ty) OR (sach y)) dang xay hoi. hieu ((van cau) OR (van nam)) quoc ban manh hai cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach ty) OR (sach y)) dang xay hoi. hieu ((van cau) or (van nam)) quoc ban manh hai cua tre~".
• Adding a wildcard symbol may retrieve word variants: su ((sach ty) OR (sach y)) dang xay hoi. hieu ((van cau) or (van nam)) quoc ban manh hai cua tre*.