%0 Journal Article
%A H. H. Pu
%A H. W. Pu
%T On the set where an approximate derivative is a derivative
%J Colloquium Mathematicum
%D 1980
%P 155-160
%V 43
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.4064/cm-43-1-155-160/
%R 10.4064/cm-43-1-155-160
%G en
%F 10_4064_cm_43_1_155_160