Stephan Luettjohann and Hans Hoenen live next to the Dutch border in Emmerich, Germany. Hans teaches physics at Willibrord Grammar School. He has been using TeX for the past ten years for all his printed material. Stephan Luettjohann, a former student of Hans has been using TeX to prepare documents for his advanced math courses in graduate school..

Yoichi Motohashi, is a professor of math. He may be reached at Honkomagome 5-67-1-901, Tokyo 113-0021. His email address is ymoto@ math.cst.nihon-u.ac.jp