http://www.all-for-tennis.com/209111/penn-championship-regular-tennis/penn-championship-regular-duty-tennis-ball-can-3-balls.html YEARLY 2017-03-06 1 http://www.all-for-tennis.com/218351/penn-championship-regular-tennis/penn-championship-regular-duty-tennis-ball-can-3-balls.html YEARLY 2017-03-12 1