Perhaps you should try some spelling variations:
xang van » dang van, lang van, nang van
tang van » dang van, hoang van, trong van
nam thuc » nam thuoc, nam thu, nam tu
cua viet » ca viet, hoa viet, cua vat
so sach » so sanh, bo sach, co sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ty ((xang van) OR (tang van)) hoi. hieu ve ((nam thuc) OR (am thuc)) va hanh di cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ty ((xang van) OR (tang van)) hoi. hieu ve ((nam thuc) or (am thuc)) va hanh di cua viet~".
• Adding a wildcard symbol may retrieve word variants: so sach ty ((xang van) OR (tang van)) hoi. hieu ve ((nam thuc) or (am thuc)) va hanh di cua viet*.