Perhaps you should try some spelling variations:
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
mang xa » lang xa, mang may, dang xay
nang ma » tang ma, sang ma, nang cao
ve cac » va cac, vien cac
vi cua » vai cua, di cua
ve cam » ve cham, va cam, ve cai

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 y ((mang xa) OR (nang ma)) hoi. hieu ((ve cam) OR (ve cac)) thuc day hanh vi cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y ((mang xa) or (nang ma)) hoi. hieu ((ve cam) OR (ve cac)) thuc day hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach y ((mang xa) or (nang ma)) hoi. hieu ((ve cam) OR (ve cac)) thuc day hanh vi cua tre*.