Perhaps you should try some spelling variations:
"co sach tranh cong khi đong luc" » "co canh tranh cong khi đong luc", "co sach thanh cong khi đong luc", "co sach trinh cong khi đong luc", "co sach tran cong khi đong luc", "co sach tranh cong thai đong luc", "co sach tranh khong khi đong luc", "co sach tranh co khi đong luc", "bo sach tranh cong khi đong luc", "cuon sach tranh cong khi đong luc", "hoc sach tranh cong khi đong luc"
"so sach nganh y khi đong luc" » "so sach ngan y khi đong luc", "so cac nganh y khi đong luc", "so sach danh y khi đong luc", "so sanh nganh y khi đong luc", "bo sach nganh y khi đong luc", "hoc sach nganh y khi đong luc", "so sach nganh ly khi đong luc", "so sach nganh ky khi đong luc", "so sach nganh my 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: (("co sach tranh cong khi đong luc") or ("so sach nganh y khi đong luc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("co sach tranh cong khi đong luc") OR ("so sach nganh y khi đong luc")).
• Removing quotes may allow a broader search: (( co sach tranh cong khi đong luc ) or ( so sach nganh y khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (("co sach tranh cong khi đong luc") or ("so sach nganh y khi đong luc"))*.