SpringerLink (Online service) & Forrester, C. (2011). High above: The untold story of Astra, Europe's leading satellite company. Springer eBooks..
Chicago-viite (17. p.)SpringerLink (Online service) ja Chris Forrester. "High Above: The Untold Story of Astra, Europe's Leading Satellite Company." Springer EBooks. 2011.
MLA-viite (9. p.)SpringerLink (Online service) ja Chris Forrester. "High Above: The Untold Story of Astra, Europe's Leading Satellite Company." Springer EBooks., 2011.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.