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
doi cua » dai cua, hoi cua
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va
cua tre » cua te, cuu tre, cua triet
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 va) or (hieu qua)) nam thuc ((dao hanh) or (day thanh)) doi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang x hoi. ((hieu va) OR (hieu qua)) nam thuc ((dao hanh) OR (day thanh)) doi cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang x hoi. ((hieu va) or (hieu qua)) nam thuc ((dao hanh) or (day thanh)) doi cua tre*.