Perhaps you should try some spelling variations:
theo hanh » them thanh, thuc hanh, thi hanh
lam dinh » nam dinh, lam tinh, lam linh
dinh duc » minh duc, ninh duc, sinh duoc
tinh duc » minh duc, ninh duc, sinh duoc
heo van » theo van, ho van, hao van
van lam » van nam
hanh va » hang va, hanh vi
va tinh » may tinh

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: (( heo van lam dinh duc. ) OR ( theo hanh va tinh duc. ))~.
• Adding a wildcard symbol may retrieve word variants: (( heo van lam dinh duc. ) or ( theo hanh va tinh duc. ))*.