Perhaps you should try some spelling variations:
"su sach tranh cong thai đong luc" » "su sach thanh cong thai đong luc", "su sach trinh cong thai đong luc", "su sach tran cong thai đong luc", "su sach tranh cong hai đong luc", "su sach tranh hong thai đong luc", "su sach tranh cong thanh đong luc", "so sach tranh cong thai đong luc", "vu sach tranh cong thai đong luc"
"su canh tranh cho khi đong luc" » "su canh trinh cho khi đong luc", "su canh trang cho khi đong luc", "su canh tranh co khi đong luc", "suc canh tranh cho khi đong luc", "su can tranh cho khi đong luc", "su anh tranh cho khi đong luc", "su canh tranh cho ghi đong luc", "su canh tranh cao khai 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 canh tranh cho khi đong luc") or ("su sach tranh cong thai đong luc"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("su canh tranh cho khi đong luc") OR ("su sach tranh cong thai đong luc")).
• Removing quotes may allow a broader search: (( su canh tranh cho khi đong luc ) or ( su sach tranh cong thai đong luc )).
• Adding a wildcard symbol may retrieve word variants: (("su canh tranh cho khi đong luc") or ("su sach tranh cong thai đong luc"))*.