Perhaps you should try some spelling variations:
hanh trung » thanh trung, hanh trang, manh trung
hieu quan » lieu quan, thien quan, lien quan
trung hoc » trung quoc
hang nong » thang long, han tong
hoc hang » hoc hanh, hoc bang, hoc tang
nong dan » cong dan, nong san, nguong dan
toan cau » toan ban, toan tap, toan tai
toan cao » toan ban, toan tap

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: ho ((hieu quan) OR (hieu qua)) - hanh trung hoc hang nong dan ((toan cau) OR (toan cao))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((hieu quan) OR (hieu qua)) - hanh trung hoc hang nong dan ((toan cau) or (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: ho ((hieu quan) OR (hieu qua)) - hanh trung hoc hang nong dan ((toan cau) or (toan cao))*.