Perhaps you should try some spelling variations:
nha thuoc » nha nuoc, nhan thuc, nha hoc
nam thuc » nam thuoc, am thuc, nam tu
van hanh » van thanh, ban hanh, van anh
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
nang o » nang co, nang ho, nang ro
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: vu sach ky nang o hai. hieu va ((((nam thuc) OR (nam thu))) or (nha thuoc)) van hanh vi cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang o hai. hieu va ((((nam thuc) OR (nam thu))) OR (nha thuoc)) van hanh vi cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang o hai. hieu va ((((nam thuc) OR (nam thu))) or (nha thuoc)) van hanh vi cuu tre".
• Adding a wildcard symbol may retrieve word variants: vu sach ky nang o hai. hieu va ((((nam thuc) OR (nam thu))) or (nha thuoc)) van hanh vi cuu tre*.