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
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
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: su sach y nang x hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang x hoi. hieu ve cam thuc ((day hanh) OR (day nhanh)) dai cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach y nang x hoi. hieu ve cam thuc ((day hanh) or (day nhanh)) dai cua tre*.