Sipka, László (Summer 2001). "Innovators and Innovations". Hungarian Quarterly. XLII (162). Archived from the original on June 15, 2011. Retrieved August 23, 2010.
Sipka, László (Summer 2001). "Innovators and Innovations". Hungarian Quarterly. XLII (162). Archived from the original on June 15, 2011. Retrieved August 23, 2010.