Perhaps you should try some spelling variations:
trinh toan » tinh toan, thanh toan, trinh han
thi trinh » tho trinh, thi thanh, thi minh
hoc giao » hoc cao
ton giao » toan giao, so giao, don gian
tu hanh » du hanh, thuc hanh, thi hanh
lu hanh » luu hanh, du hanh, ly hanh
toan so » toan ho, toan co, than so

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

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