Perhaps you should try some spelling variations:
thuoc khanh » thuoc khang, thuoc thanh, thuc hanh
khanh trach » khanh tra
trach nhiem » trac nghiem
thu nghiem » thuc nghiem, thi nghiem
thu sach » thuat sach, thuoc sach, thu hoach
nghiem d » nghiem de, nghiem do, nghiem _
nhiem dc » nghiem de, nghiem do, nhiem va
tu sach » su sach, te sach, tu cach
dc hoc » duc hoc, du hoc, de hoc
d hoc » du hoc, ad hoc, de hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( ((thu sach) OR (tu sach)) thu nghiem d hoc ) or ( thuoc khanh trach nhiem dc hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((thu sach) OR (tu sach)) thu nghiem d hoc ) OR ( thuoc khanh trach nhiem dc hoc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( ((thu sach) OR (tu sach)) thu nghiem d hoc ) or ( thuoc khanh trach nhiem dc hoc ))*".