Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
nam thuc » nam thuoc, am thuc, nam thu
dao hanh » dao thanh, dang hanh, ban hanh
cam thuc » am thuc, cam thu, can thuc
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cua tre » cua te, cuu tre, cua triet
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: su sach ky nang x hoi. hieu va ((cam thuc) or (nam thuc)) ((dao hanh) or (day thanh)) di cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang x hoi. hieu va ((cam thuc) OR (nam thuc)) ((dao hanh) OR (day thanh)) di cua tre.
• Adding a wildcard symbol may retrieve word variants: su sach ky nang x hoi. hieu va ((cam thuc) or (nam thuc)) ((dao hanh) or (day thanh)) di cua tre*.