Perhaps you should try some spelling variations:
sach tranh » canh tranh
tinh nhiet » trinh nhiet, tinh thiet, trinh thiet
canh tinh » hanh tinh, manh tinh, canh tranh
sach tran » sach tren, vach tran, sach tham
thi quoc » thu quoc, tai quoc, thi nuoc
tu canh » thu canh, tu chanh, tu can
nhiet d » nhiet do, nhiet de, nhiet doi
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: (( tu canh tinh nhiet d hoc ) or ( tu ((sach tran) OR (sach tranh)) thi quoc hoi ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu canh tinh nhiet d hoc ) OR ( tu ((sach tran) OR (sach tranh)) thi quoc hoi )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu canh tinh nhiet d hoc ) or ( tu ((sach tran) OR (sach tranh)) thi quoc hoi ))".
• Adding a wildcard symbol may retrieve word variants: (( tu canh tinh nhiet d hoc ) or ( tu ((sach tran) OR (sach tranh)) thi quoc hoi ))*.