Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
day hanh » day nhanh, day thanh, dao hanh
dac nhan » cac nhan, danh nhan, ca nhan
day manh » van manh, duc manh, ha manh
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
vu cham » va cham, vu kham, tu cham
hieu vu » hieu va, hieu ve, hieu su
di cua » dai cua, doi cua, de cua
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: vu sach ky nang x hoi. hieu vu cham thuc ((((day hanh) or (day manh))) or (dac nhan)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. hieu vu cham thuc ((((day hanh) OR (day manh))) OR (dac nhan)) di cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. hieu vu cham thuc ((((day hanh) or (day manh))) or (dac nhan)) di cua tre*.