%0 Journal Article
%A Abel, Volker
%T Conditions for lumping the grades of a hierarchical manpower system
%J RAIRO - Operations Research - Recherche Opérationnelle
%D 1983
%P 379-383
%V 17
%N 4
%I EDP-Sciences
%U http://www.numdam.org/item/RO_1983__17_4_379_0/
%G en
%F RO_1983__17_4_379_0