Perhaps you should try some spelling variations:
trinh nghien » trinh nghe, kinh nghiem, trinh thiet
tranh nghiem » trac nghiem, trai nghiem, doanh nghiep
trach nhiem » trac nghiem
ban trach » ban thanh, ban sach, ban mach
nhiem du » hiem du, nghiem dau, nhiem huu
thu sach » tu sach, thuat sach, thuoc sach
thu ban » thu hang
du hoc » tu hoc, duoc 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 ban trach nhiem du hoc ) or ( thu sach ((tranh nghiem) or (trinh nghien)) ad hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( thu ban trach nhiem du hoc ) OR ( thu sach ((tranh nghiem) OR (trinh nghien)) ad hoc )).
• Adding a wildcard symbol may retrieve word variants: (( thu ban trach nhiem du hoc ) or ( thu sach ((tranh nghiem) or (trinh nghien)) ad hoc ))*.