Perhaps you should try some spelling variations:
cham thuc » nham thuc, pham thuc, tham thuc
day nhanh » day thanh, duy nhanh, dac nhan
va triet » va thiet, va trien, ve triet
duc manh » suc manh, duc anh, duc minh
cua tre » cua te, cuu tre, cua triet
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
ve cham » va cham, ve chat, vu cham
hieu ve » hieu va, hieu van
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 ky nang x hoi. hieu ve cham thuc ((duc manh) or (day nhanh)) de ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu ve cham thuc ((duc manh) OR (day nhanh)) de ((cua tre) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu ve cham thuc ((duc manh) or (day nhanh)) de ((cua tre) or (va triet))*.