Perhaps you should try some spelling variations:
pham thuc » phap thuc, pham chuc, nham thuc
day thanh » dao thanh, dat thanh, da thanh
cham thuc » nham thuc, tham thuc, pham thuoc
day hanh » day nhanh, dao hanh, day manh
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
de cua » le cua, te cua, dieu cua
x hoi » xa hoi, o hoi, x ho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. hieu ve ((cham thuc) OR (pham thuc)) ((day hanh) OR (day thanh)) de cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang x hoi. hieu ve ((cham thuc) OR (pham thuc)) ((day hanh) or (day thanh)) de cua tre~".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. hieu ve ((cham thuc) OR (pham thuc)) ((day hanh) or (day thanh)) de cua tre*.