Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
phan cua » nhan cua, than cua, phat cua
va thanh » gia thanh, va tinh, le thanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
o hoc » co hoc, mo hoc, so hoc
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: tu sach ky nang ((x hoi) or (o hoc)). hieu va nam thuc ((va thanh) OR (ban thanh)) phan cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang ((x hoi) OR (o hoc)). hieu va nam thuc ((va thanh) OR (ban thanh)) phan cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang ((x hoi) or (o hoc)). hieu va nam thuc ((va thanh) OR (ban thanh)) phan cua viet*".