Perhaps you should try some spelling variations:
"tu sach tich su - toan giao" » "tu sach tich su - ton giao", "tu sach tich su - toan cao", "tu sach tich su - hoa giao", "tu mach tich su - toan giao", "tu sach kinh su - toan giao", "tu suc tich su - toan giao", "thu sach tich su - toan giao", "su sach tich su - toan giao", "te sach tich su - toan giao", "tu sach lich su - toan giao", "tu sach tich du - toan giao", "tu sach tinh su - toan giao"
"vu phan tich so - don gian" » "vu phan tich so - dan gian", "va phan tich so - don gian", "su phan tich so - don gian", "uu phan tich so - don gian", "vu phan tich bao - don gian", "vu phan tinh son - don gian"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("vu phan tich so - don gian") or ("tu sach tich su - toan giao"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("vu phan tich so - don gian") OR ("tu sach tich su - toan giao")).
• Removing quotes may allow a broader search: (( vu phan tich so - don gian ) or ( tu sach tich su - toan giao )).
• Adding a wildcard symbol may retrieve word variants: (("vu phan tich so - don gian") or ("tu sach tich su - toan giao"))*.