Perhaps you should try some spelling variations:
"nhung thoi luan van. biet the hieu luc xuc" » "nhung thi luan van. biet the hieu luc xuc", "phung thi luan van. biet the hieu luc xuc", "nhung loi luan van. biet the hieu luc xuc", "nhung hoi luan van. biet the hieu luc xuc", "nhung thai luan van. biet the hieu luc xuc", "nhung thoi luan van. biet the hieu luat xuc"
"phung mai quan vag. biet the hieu qua xuc" » "phuong mai quan vag. biet the hieu qua xuc", "thuong mai quan vag. biet the hieu qua xuc", "phung manh quan vag. biet the hieu qua xuc", "phung hai quan vag. biet the hieu qua xuc", "phung ban quan vag. biet the hieu qua xuc", "phung mai quan va. biet the hieu qua xuc", "phung mai quan van. biet the hieu qua xuc", "phung mai quan lang. biet the hieu qua xuc", "phung mai quan vag. biet the hieu qua tuc", "phung mai quan vag. biet the hieu quang xuc", "phung mai quan vag. biet the hieu qua buoc"

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (("nhung thoi luan van. biet the hieu luc xuc") OR ("phung mai quan vag. biet the hieu qua xuc"))~.
• Removing quotes may allow a broader search: (( nhung thoi luan van. biet the hieu luc xuc ) or ( phung mai quan vag. biet the hieu qua xuc ))~.
• Adding a wildcard symbol may retrieve word variants: (("nhung thoi luan van. biet the hieu luc xuc") or ("phung mai quan vag. biet the hieu qua xuc"))*.