Perhaps you should try some spelling variations:
nghiem ban » nghiem xuan, nghiep bang, nghiem va
nghiem van » nghiem va, nghiep van, nghiem xuan
tranh vat » trinh vat, tranh va, tranh van
hoc canh » hoc anh, hoc can, hoc hanh
te sach » toc sach
vat d » vat da, vat de, vat _
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: (( hoc canh tranh vat d hoc ) or ( te sach tranh ((nghiem ban) OR (nghiem van)) hoc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( hoc canh tranh vat d hoc ) OR ( te sach tranh ((nghiem ban) OR (nghiem van)) hoc )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( hoc canh tranh vat d hoc ) or ( te sach tranh ((nghiem ban) OR (nghiem van)) hoc ))".
• Adding a wildcard symbol may retrieve word variants: (( hoc canh tranh vat d hoc ) or ( te sach tranh ((nghiem ban) OR (nghiem van)) hoc ))*.