A friend recently sent a copy of this flyer to me from the 28th Annual convention of the Iowa Chiropractic Society. The dates were April 18-20, 1959. What I find interesting is that fact that Dr. Weldon Derifield taught several hours on Pelvic Sacral Technic while Dr. Clay Thompson did one hour of a film and talk about his trip to Europe, presumably to 1958's World's Fair in Brussels! BJ showed up on Sunday for an hour and a half, too. One of the exhibitors was Vitamin Products Co., which was the name of Royal Lee's supplement company before it became Standard Process, Inc. Enjoy!