%0 Journal Article
%A
%A
%A
%T Group theory and many body diagrams I. Classification and structure of diagrams
%D 1975
%R 10.1098/rspa.1975.0108
%J Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences
%P 387-401
%V 344
%N 1638
%X Each term in the diagrammatic expansion of a many body system is identified with an equivalence class of permutations. The combinatorial aspects of the expansion are studied and the structure of the diagrams analysed by the methods of group theory.
%U http://rspa.royalsocietypublishing.org/content/royprsa/344/1638/387.full.pdf