* separar palavras-chave com vírgula
Melhores sites Persistence 1-7:
1.
studentclearinghouse.org 
52,000

2.
javacodegeeks.com 
41,574

3.
awakenthegreatnesswithin.com 
11,514

4.
accord-soft.com 
327

5.
success.net 
212

6.
laopiniondemurcia.es 
31,198

7.
postcourier.com.pg 
27,300

8.
missoandfriends.com 
26,439

9.
activityvillage.co.uk 
24,422

10.
krazydad.com 
24,314

11.
sudoku.name 
24,042

12.
coolsite.co.il 
23,816

13.
youplay.com 
22,309

14.
mindgames.com 
22,230

15.
kakuroconquest.com 
16,715