Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
cam thuc » am thuc, nam thuc, cam thu
day hanh » day thanh, dao hanh, day manh
so sach » bo sach, co sach, hoc sach
hieu ve » hieu va, hieu van
so sanh » do sanh
cuu tre » cua tre, cau tren, cau treo
ve cam » ve cham, ve cac, va cam
di cuu » di cau, di cua, dinh cuu
x hoi » xa hoi, o hoi, x ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sach) OR (so sanh)) ky nang x 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: ((so sach) OR (so sanh)) ky nang x hoi. hieu ve cam thuc ((day hanh) OR (day nhanh)) di cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((so sach) OR (so sanh)) ky nang x hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) di cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((so sach) OR (so sanh)) ky nang x hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) di cuu tre*.