back Instruction of these pages Welcome to my web site. ABOUT COPYING: It is free and allowed to copy and use all my text, photos and drawings in no-commercial use (personal, in education, ...). In commercial use: please contact me first. I hope that in larger citings the name of source material is mentioned and the direct content has not been changed essentially. FEEDBACK: I would love to have all kinds of feedback, links and other hints. I try to build as useful web site as possible. Good luck and all the best to You, sincerely Pekka.