Perhaps you should try some spelling variations:
"su xac danh co khi đong luc" » "su xac dinh co khi đong luc", "su tac danh co khi đong luc", "su sach danh co khi đong luc", "su xac danh cho khi đong luc", "su xac doanh co khi đong luc", "su xac anh co khi đong luc", "pu xac danh co khi đong luc", "su cac danh co khi đong luc"
"su sach han cong khi đong luc" » "su sach tham cong khi đong luc", "su sach danh cong khi đong luc", "su sach nang cong khi đong luc", "su sach phan cong khi đong luc", "su sach hang cong khi đong luc", "su sach hanh cong khi đong luc", "su sach han cong thai đong luc", "su sach han khong khi đong luc", "su sach han cong ha đong luc", "so sach han cong khi đong luc", "vu sach han cong khi đong luc"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("su xac danh co khi đong luc") or ("su sach han cong khi đong luc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("su xac danh co khi đong luc") OR ("su sach han cong khi đong luc"))*.
• Removing quotes may allow a broader search: (( su xac danh co khi đong luc ) or ( su sach han cong khi đong luc ))*.