Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
day hanh » day thanh, dao hanh, day manh
cam thuc » am thuc, nam thuc, cam thu
sach ky » sac ky, sach y, sach kem
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
sach ty » sach y, sach tu, sach thu
nang o » nang co, nang ho, nang ro
di cuu » di cau, di cua, dinh cuu
ve cam » ve cham, ve cac, va cam
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach ky) or (sach ty)) nang o hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) di cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach ky) OR (sach ty)) nang o hoi. hieu ve cam thuc ((day hanh) OR (day nhanh)) di cuu tre.
• Adding a wildcard symbol may retrieve word variants: su ((sach ky) or (sach ty)) nang o hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) di cuu tre*.