@article{Zheng, author = {Zheng, Xizhong}, title = {Recursive approximability of real numbers}, language = {de} } @article{Zheng, author = {Zheng, Xizhong}, title = {Closure properties on real numbers under limits and computable operators}, language = {en} } @article{RettingerZhengGengleretal., author = {Rettinger, Robert and Zheng, Xizhong and Gengler, Romain and Braunm{\"u}hl, Burchard von}, title = {Monotonically computable real numbers}, language = {en} }