Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
nam thuc » am thuc, nam thu, nam tu
vu sach » vu bach, su sach, vu khach
hieu ve » hieu va, hieu van
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
vi cua » vai cua, di cua
x hoi » xa hoi, o hoi, 5 hoi

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 y nang ((x hoi) or (x ho)). hieu ve ((nam thuc) or (nam thuoc)) va danh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y nang ((x hoi) OR (x ho)). hieu ve ((nam thuc) OR (nam thuoc)) va danh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach y nang ((x hoi) or (x ho)). hieu ve ((nam thuc) or (nam thuoc)) va danh vi cua tre*.