%0 Journal Article
%A Andrea Sorbi
%T Comparing $∏^0_2$ sets of the Baire space by means of general recursive operators
%J Fundamenta Mathematicae
%D 1991
%P 1-12
%V 138
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/articles/10.4064/fm-138-1-1-12/
%R 10.4064/fm-138-1-1-12
%G en
%F 10_4064_fm_138_1_1_12