Cafferky, Michael E. "Michael E. Cafferky's FREE Word-of-mouth Marketing TIPS"
http://www.oocities.org/WallStreet/6246
Cates, Bill "Unlimited Referrals", $alesDoctors (on-line) Magazine, Power Point Communication
http://salesdoctors.com/referral/index.htm
Garfinkel, David "How to Get More Referrals than You Ever Dreamed Of", Sales Plus
http://www.salesplus.com/referral.html
McCraigh, Jim "Seven Referral Marketing Secrets"
http://www.tpsn.com/cc_art1.html
Misner, Ivan Business Network International
http://www.bninet.com
"Referral Techniques", (Commercial referral marketing products for sale)
http://www.ipsdirect.com/pbs.ref.html
Silverman, George "How to Harness Word of Mouth", Market Navigation, Inc.
http://ww./mnav.com/wom.htm