Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
day hanh » day nhanh, day thanh, dao hanh
thuc day » thuc dan, thuc vat
cao hoc » co hoc, cho hoc, chat hoc
van cam » van lam, van cau, van dam
so sach » so sanh, bo sach, co sach
hanh di » hanh vi, hanh de, hang di
vu sach » vu bach, su sach, vu khach
v nang » va nang, vu nang, van nang
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: ((vu sach) OR (so sach)) v nang cao hoc. hieu ((van cam) OR (van nam)) thuc day hanh di cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (so sach)) v nang cao hoc. hieu ((van cam) OR (van nam)) thuc day hanh di cua viet~".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (so sach)) v nang cao hoc. hieu ((van cam) OR (van nam)) thuc day hanh di cua viet*.