TY - THES A1 - Zheng, Xizhong T1 - Effective Hierarchy of Real Numbers Y1 - 2008 UR - https://opus4.kobv.de/opus4-UBICO/frontdoor/index/index/docId/4030 SN - 978-3-8322-6343-0 PB - Shaker CY - Aachen ER -