TY - BOOK A1 - Vasileiadou, Eleni Magdalini A1 - Ullrich, Sebastian A1 - Tamm, Gerrit T1 - Cloud Computing Definitions and Approaches - Levels of Abstraction: IAAS, PAAS, SAAS Y1 - 2011 PB - Asperado GmbH & SRH Hochschule Berlin ER -