Perhaps you should try some spelling variations:
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
cam thuc » am thuc, nam thuc, cam thu
su sach » so sach, vu sach
sang ma » tang ma, sang tao, mang may
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
nang ma » tang ma, nang cao, mang may
mang xa » lang xa, mang may, dang xay
ve cam » ve cham, ve cac, va cam
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: su sach y ((mang xa) OR (((nang ma) OR (sang ma)))) hoi. hieu ve cam 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) OR (sang ma)))) hoi. hieu ve cam thuc day hanh vi cua tre~".
• Adding a wildcard symbol may retrieve word variants: su sach y ((mang xa) or (((nang ma) OR (sang ma)))) hoi. hieu ve cam thuc day hanh vi cua tre*.