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