Dear all, I would like to thank everybody who contributed to this topic. It was an eye opener for me, and especially the very interesting article cited by Alejandro (or Alex Fernandez-Martinez; thank you!) proved to be a great read. Thanks again for taking the time! Cheers, Herwig https://www.mindat.org/user-86.html <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> Virusvrij. www.avg.com <http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>