Perhaps you should try some spelling variations:
mach tinh » mach tich, manh tinh, trach tinh
toan giao » ton giao, toan cao, hoa giao
canh tinh » manh tinh, canh tranh, nhanh tinh
hanh tinh » hanh trinh, nhanh tinh, thanh tinh
hoc giao » hoc cao
tu mach » tu cach, tu manh, tu hach
tinh du » tinh duc, tinh dau, tich du

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 tinh du - toan giao ) or ( tu ((canh tinh) OR (hanh tinh)) du - hoc giao ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( tu mach tinh du - toan giao ) OR ( tu ((canh tinh) OR (hanh tinh)) du - hoc giao )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( tu mach tinh du - toan giao ) or ( tu ((canh tinh) OR (hanh tinh)) du - hoc giao ))".
• Adding a wildcard symbol may retrieve word variants: (( tu mach tinh du - toan giao ) or ( tu ((canh tinh) OR (hanh tinh)) du - hoc giao ))*.