Perhaps you should try some spelling variations:
"so sach trinh co khi đong luc" » "so sach tranh co khi đong luc", "so hanh trinh co khi đong luc", "so sach kinh co khi đong luc", "so sach trinh do khi đong luc", "so sach trinh cong khi đong luc", "so sach trinh hoa khi đong luc", "so sanh trinh co khi đong luc", "bo sach trinh co khi đong luc", "co sach trinh co khi đong luc"
"co canh tranh cuoc khi đong luc" » "co canh tranh duoc khi đong luc", "co canh tran quoc khi đong luc", "co canh trong cuoc khi đong luc", "co canh tranh cuoc khoi đong luc", "co canh tranh cuoc thi đong luc", "co canh tranh buoc khoi đong luc", "bo canh tranh cuoc khi đong luc", "co anh tranh cuoc khi đong luc", "co cach tranh cuoc 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: (("so sach trinh co khi đong luc") or ("co canh tranh cuoc khi đong luc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("so sach trinh co khi đong luc") OR ("co canh tranh cuoc khi đong luc")).
• Removing quotes may allow a broader search: (( so sach trinh co khi đong luc ) or ( co canh tranh cuoc khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (("so sach trinh co khi đong luc") or ("co canh tranh cuoc khi đong luc"))*.