Perhaps you should try some spelling variations:
tranh nghiem » trac nghiem, trinh nghien, trai nghiem
tranh nghiep » doanh nghiep, trinh nghien, trac nghiem
trach nhiem » trac nghiem
sach tranh » canh tranh
nghiep tu » nghiep vu, nghiep vua, nghiep cua
so sach » so sanh, bo sach, co sach
vu sach » vu bach, su sach, vu khach
tu hoc » te 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: (( so sach tranh nghiep tu hoc ) or ( vu sach ((tranh nghiem) OR (trach nhiem)) d hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( so sach tranh nghiep tu hoc ) OR ( vu sach ((tranh nghiem) OR (trach nhiem)) d hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( so sach tranh nghiep tu hoc ) or ( vu sach ((tranh nghiem) OR (trach nhiem)) d hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( so sach tranh nghiep tu hoc ) or ( vu sach ((tranh nghiem) OR (trach nhiem)) d hoc ))*.