%0 Journal Article %T Dropping diversity of products of large US firms: Models and measures %A Nambiar, Ananthan %A Rubel, Tobias %A McCaull, James %A deVries, Jon %A Bedau, Mark %J PLoS ONE %V 17 %N 3 %D 2022-03-16 %I Public Library of Science %~ DeepDyve