Read the Boffetta et al. (2010) article (attached). Identify any potential threats to internal or external validity in the article. Do you notice any potential problems with the conclusions?
http://www.socialresearchmethods.net/kb/external.php -external validity review
http://www.socialresearchmethods.net/kb/intval.php -internal validity review
1 page AMA format
Attachment:- fruitvegiescancer.rar