Perhaps you should try some spelling variations:
trach nhiem » trac nghiem
nhiem thuoc » nghiem thuoc, nhiem thuc, nhiem thuong
san trach » sat trach, can tranh, lan tranh
thuoc hoc » thuoc ho, thuoc nhom, thuong hoc
tac nhiem » trac nghiem, tac nghiep, thai nhiem
canh tac » canh tay, canh giac, cong tac
tu canh » thu canh, tu chanh, tu can
huu hoc » huu ho, cuu hoc, huu loc
te san » te ban, ke san, tu san

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( te san trach nhiem thuoc hoc ) or ( tu canh tac nhiem huu hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te san trach nhiem thuoc hoc ) OR ( tu canh tac nhiem huu hoc )).
• Adding a wildcard symbol may retrieve word variants: (( te san trach nhiem thuoc hoc ) or ( tu canh tac nhiem huu hoc ))*.