Perhaps you should try some spelling variations:
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cuu tre, cua triet
tang ma » mang may, tang van
va dao » ca dao
vi cua » vai cua, di cua
ve cam » ve cham, ve cac, va cam

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky ((tang ma) or (nang cao)) hoi. hieu ((ve cam) or (va dao)) thuc day hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((tang ma) OR (nang cao)) hoi. hieu ((ve cam) OR (va dao)) thuc day hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((tang ma) or (nang cao)) hoi. hieu ((ve cam) or (va dao)) thuc day hanh vi cua tre*.