Perhaps you should try some spelling variations:
ton giao » toan giao, hoc giao, don gian
tu mach » tu cach, tu manh, tu sach
su sach » so sach, vu sach
tich su » tich du, tich so, tinh su
tu hach » tu cach, tu sach, vu khach
tu hanh » du hanh, lu hanh, thuc hanh
so giao » so giai, hoc giao

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