Bláthy, Ottó Titusz. Budapest University of Technology and Economics, National Technical Information Centre and Library. [Feb 29, 2012]. (原始内容存档于2013-05-24).
Bláthy, Ottó Titusz. Budapest University of Technology and Economics, National Technical Information Centre and Library. [Feb 29, 2012]. (原始内容存档于2013-05-24).