Perhaps you should try some spelling variations:
nha thuoc » nha nuoc, nhan thuc, nha hoc
van hanh » van thanh, ban hanh, van anh
nam thuc » nam thuoc, am thuc, nam thu
su sach » vu sach
hieu va » lieu va, hieu qua
so sach » so sanh, bo sach, co sach
cuu tre » cua tre, cau tren, cau treo
nang o » nang co, nang ho, nang ro
y nang » ky nang, ly nang, v nang
vi cuu » vi luu, vinh cuu
o hai » co hai, so hai, o lai

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) OR (so sach)) y nang o hai. hieu va ((nam thuc) or (nha thuoc)) van hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) y nang o hai. hieu va ((nam thuc) OR (nha thuoc)) van hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (so sach)) y nang o hai. hieu va ((nam thuc) or (nha thuoc)) van hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (so sach)) y nang o hai. hieu va ((nam thuc) or (nha thuoc)) van hanh vi cuu tre*.