@booklet {76, title = {How Clever-based Clouds Conceive Horizontal And Vertical Federations}, journal = {Computers and Communications (ISCC), 2011 IEEE Symposium on}, year = {2011}, pages = {167{\textendash}172}, publisher = {IEEE Computer Society}, address = {Los Alamitos, CA}, author = {Francesco Tusa and Antonio Celesti and Maurizio Paone and Massimo Villari and Antonio Puliafito} }