Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
thuc ban » thuoc ban, thuc dan, thuc van
hieu va » hieu qua
thu ban » thu hang
nang xa » nang x, lang xa, nang ma
hang vi » hang va, hanh vi, hang di
su sach » so sach, vu sach
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) OR (thu 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) OR (thu ban)) hang vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang xa hoi. ((hieu va) or (lieu va)) nam ((thuc ban) OR (thu 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) OR (thu ban)) hang vi cua viet*.