Perhaps you should try some spelling variations:
day nhanh » day thanh, duy nhanh, dac nhan
day hanh » day thanh, dao hanh, da hanh
day manh » van manh, duc manh, ha manh
dinh cuu » dinh chi
cam thuc » am thuc, nam thuc, cam thu
bo sach » co sach, hoc sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cuu tre » cua tre, cau tren, cau treo
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: bo sach ky nang x hoi. hieu ve cam thuc ((((day hanh) OR (day manh))) or (day nhanh)) dinh cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ky nang x hoi. hieu ve cam thuc ((((day hanh) OR (day manh))) OR (day nhanh)) dinh cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach ky nang x hoi. hieu ve cam thuc ((((day hanh) OR (day manh))) or (day nhanh)) dinh cuu tre".
• Adding a wildcard symbol may retrieve word variants: bo sach ky nang x hoi. hieu ve cam thuc ((((day hanh) OR (day manh))) or (day nhanh)) dinh cuu tre*.