Perhaps you should try some spelling variations:
mach dinh » hoach dinh, xac dinh, mach dien
toan giao » toan cao, hoa giao
cach dinh » cac dinh, cach kinh, hoach dinh
ton giao » hoc giao, so giao, hoa giao
don gian » dan gian
tu mach » tu manh, tu hach, tu sach
dinh du » dinh duc, dinh cu, dinh tu
tu cach » tu cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( tu mach dinh du - toan giao ) or ( tu cach dinh du - ((ton giao) OR (don gian)) ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu mach dinh du - toan giao ) OR ( tu cach dinh du - ((ton giao) OR (don gian)) )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu mach dinh du - toan giao ) or ( tu cach dinh du - ((ton giao) OR (don gian)) ))".
• Adding a wildcard symbol may retrieve word variants: (( tu mach dinh du - toan giao ) or ( tu cach dinh du - ((ton giao) OR (don gian)) ))*.