On Thursday February 13 2020, Paul Campbell from the United States left the following message for Frederick Solomon:
"Fred, I finally retired from Beloit last August (53 years teaching, 42 at Beloit) but am now busy revising the For All Practical Purposes book. The publisher wants to contact you for permission to use your figures again in the new edition. Your old email doesn't work anymore. So I went looking for you, located an address and phone for you in Horse Shoe. How are you and Louise doing? Best wishes, Paul C."
Paul Campbell left an e-mail address and a telephone number.