Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
hoc sac » hoc sach, hoc cac, hoc mac
hieu va » hieu qua
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu van
sac ky » cac ky, sai ky
va cua » va chua, via cua, ca 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: hoc sac ky nang x hoi. ((hieu ve) or (((lieu va) or (hieu va)))) nam thuc va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sac ky nang x hoi. ((hieu ve) OR (((lieu va) OR (hieu va)))) nam thuc va hanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: hoc sac ky nang x hoi. ((hieu ve) or (((lieu va) or (hieu va)))) nam thuc va hanh va cua tre*.