Perhaps you should try some spelling variations:
"su sach trinh do khi đong luc" » "su hanh trinh do khi đong luc", "su sach kinh do khi đong luc", "su sach tren do khi đong luc", "su sach trinh ky khi đong luc", "so sach trinh do khi đong luc", "vu sach trinh do khi đong luc", "su sach trinh doi khi đong luc", "su sach trinh do thi đong luc", "su sach trinh co khi đong luc"
"su sach tranh cua khi đong luc" » "su canh tranh cua khi đong luc", "su sach doanh cua khi đong luc", "su sach manh cua khi đong luc", "so sach tranh cua khi đong luc", "vu sach tranh cua khi đong luc", "su sach tranh cua khoi đong luc", "su sach tranh cu khi đong luc", "su sach tranh cua chi 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 tranh cua khi đong luc") or ("su sach trinh do khi đong luc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("su sach tranh cua khi đong luc") OR ("su sach trinh do khi đong luc")).
• Removing quotes may allow a broader search: (( su sach tranh cua khi đong luc ) or ( su sach trinh do khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (("su sach tranh cua khi đong luc") or ("su sach trinh do khi đong luc"))*.