Business Grzegorz Gierejko, Sagem Communication 21 November 2005 In his career he has worked for HBO and Philips. Gierejko is a graduate of the psychology department at Cardinal Stefan Wyszyński University. He also graduated with an MBA from the Warsaw School of Technology. More from Business All Yesterday 88.3% of Poles choose products from promotional flyers when shopping 2 days ago Poland prepares major highway upgrades as congestion grows 2 days ago Paid DataWalk secures U.S. patent protection for AI technology