OpenStack in Production: A tale of 3 OpenStack Clouds (http://openstack-in-production.blogspot.com/2013/09/a-tale-of-3-openstack-clouds-50000.html)
Review of CERN Data Centre Infrastructure (http://cern.ch/go/N8wp)
CERN Cloud Infrastructure User Guide (http://information-technology.web.cern.ch/book/cern-private-cloud-user-guide)