Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
thien van » thi van
thuoc van » thuoc va, thuc van, thuoc ban
van doanh » toan doanh, van dong, van thanh
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, lieu va, hieu ve
doanh va » doan va, doanh tai, doanh cua
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
va cua » va chua, via cua, ca cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y nang ma hoi. ((hieu van) or (thien van)) nam thuoc van doanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang ma hoi. ((hieu van) OR (thien van)) nam thuoc van doanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y nang ma hoi. ((hieu van) or (thien van)) nam thuoc van doanh va cua tre*.