%0 Journal Article %A Richard B. Edelman %T Telecommunications betas %B Are they stable and unique? %D 1983 %R 10.3905/jpm.1983.408936 %J The Journal of Portfolio Management %P 46-52 %V 10 %N 1 %U https://jpm.pm-research.com/content/iijpormgmt/10/1/46.full.pdf