Robert Rettinger Xizhong Zheng Romain Gengler Burchard von Braunmühl Weakly Computable Real Numbers and Total Computable Real Functions. 586-595 2001 conf/cocoon/2001 COCOON http://link.springer.de/link/service/series/0558/bibs/2108/21080586.htm db/conf/cocoon/cocoon2001.html#RettingerZGB01