Wetterberg, Gunnar (2005). "Den mäktige Oxenstierna". popularhistoria.se (in Swedish). Populär Historia. Archived from the original on 27 June 2007. Retrieved 2 July 2009.
Wetterberg, Gunnar (2005). "Den mäktige Oxenstierna". popularhistoria.se (in Swedish). Populär Historia. Archived from the original on 27 June 2007. Retrieved 2 July 2009.