Perhaps you should try some spelling variations:
trach nhiem » trac nghiem
thuoc nhom » thuoc ho
thuoc hoc » thuoc ho, thuong hoc, duoc 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 sat » te dat, te 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 sat trach nhiem ((thuoc hoc) OR (thuoc nhom)) ) or ( tu canh tac nhiem huu hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( te sat trach nhiem ((thuoc hoc) OR (thuoc nhom)) ) OR ( tu canh tac nhiem huu hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( te sat trach nhiem ((thuoc hoc) OR (thuoc nhom)) ) or ( tu canh tac nhiem huu hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( te sat trach nhiem ((thuoc hoc) OR (thuoc nhom)) ) or ( tu canh tac nhiem huu hoc ))*.