@article{CM_1969__21_4_376_0, author = {Flor, Peter}, title = {On groups of non-negative matrices}, journal = {Compositio Mathematica}, pages = {376--382}, publisher = {Wolters-Noordhoff Publishing}, volume = {21}, number = {4}, year = {1969}, mrnumber = {257115}, zbl = {0194.34005}, language = {en}, url = {http://archive.numdam.org/item/CM_1969__21_4_376_0/} }