Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam thu
thuc ban » thuoc ban, thuc dan, thu ban
ban hang » ngan hang
cua viet » ca viet, hoa viet, cua vat
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
hang vi » hang va, hanh vi, hang di
y nang » ky nang, ly nang, v nang
vi cua » vai cua, di cua

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 y nang xa hoi. ((hieu va) or (lieu va)) nam thuc ban hang vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. ((hieu va) OR (lieu va)) nam thuc ban hang vi cua viet.
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. ((hieu va) or (lieu va)) nam thuc ban hang vi cua viet*.