Perhaps you should try some spelling variations:
"tu sach trinh san - so giao" » "tu sach tranh san - so giao", "tu hanh trinh san - so giao", "tu sach kinh san - so giao", "tu sach trinh han - so giao", "tu sach trinh quan - so giao", "tu sach trinh toan - so giao", "thu sach trinh san - so giao", "su sach trinh san - so giao", "te sach trinh san - so giao", "tu sach trinh san - so giai", "tu sach trinh san - hoc giao"
"tu hanh lich su - ton giao" » "tu hinh lich su - ton giao", "tu khanh linh su - ton giao", "tu hanh thich su - ton giao", "tu hanh lich su - toan giao", "tu hanh lich su - hoc giao", "tu hanh lich su - don gian", "du hanh lich su - ton giao", "lu hanh lich su - ton giao", "thuc hanh lich su - ton giao"

Try widening your search to All Fields.

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

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