Perhaps you should try some spelling variations:
"su sach trinh viet khi đong luc" » "su sach tranh viet khi đong luc", "su hanh trinh viet khi đong luc", "su sach kinh viet khi đong luc", "su sach ninh viet khi đong luc", "su sach trinh vat khi đong luc", "su sach trinh viet khoa đong luc", "su sach trinh viet nhin đong luc", "su sach trinh viet ha đong luc", "so sach trinh viet khi đong luc", "vu sach trinh viet khi đong luc"
"su hanh chinh do khi đong luc" » "su hanh chinh so khi đong luc", "su hanh chinh du khi đong luc", "su hanh chinh cho khi đong luc", "su thanh chinh do khi đong luc", "du hanh chinh do khi đong luc", "lu hanh chinh do khi đong luc", "su hanh chinh doi khi đong luc", "su hanh chinh do thi đong luc", "su hanh chinh co khi đong luc"

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: (("su sach trinh viet khi đong luc") or ("su hanh chinh do khi đong luc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("su sach trinh viet khi đong luc") OR ("su hanh chinh do khi đong luc")).
• Removing quotes may allow a broader search: (( su sach trinh viet khi đong luc ) or ( su hanh chinh do khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (("su sach trinh viet khi đong luc") or ("su hanh chinh do khi đong luc"))*.