@article{Frank_2016, doi = {10.1089/ast.2015.1418}, url = {http://dx.doi.org/10.1089/ast.2015.1418}, year = {2016}, month = {may}, publisher = {Mary Ann Liebert Inc}, volume = {16}, number = {5}, pages = {359--362}, author = {A. Frank and W.T. Sullivan}, title = {{A New Empirical Constraint on the Prevalence of Technological Species in the Universe}}, journal = {Astrobiology}, }