[1]. Charlie Brown, “NCH Annual Topline Coupon Facts,” NCH Marketing Resource Center, January 2012, https://www.nchmarketing.com/resourcecenter/couponknowledgestream4a.aspx?id=7317.
[2]. Ibid.
[3]. “Frequently Asked Questions,” Coupon Information Corporation, http://www.couponinformationcenter.com/faq.php.