Frid-Nielsen, Niels (1987). "En Flipper i Firserne" [A Flipper in the Eighties]. MM Magazine (in Danish). 4: 32–34. Archived from the original on 2012-03-30. Retrieved 2011-09-23.
Gjedsted, Jens Jørn (1976). "Bifrost". MM Magazine. 5: 32–36. Archived from the original on 2012-03-30. Retrieved 2009-03-07.
Frid-Nielsen, Niels (1987). "En Flipper i Firserne" [A Flipper in the Eighties]. MM Magazine (in Danish). 4: 32–34. Archived from the original on 2012-03-30. Retrieved 2011-09-23.
Gjedsted, Jens Jørn (1976). "Bifrost". MM Magazine. 5: 32–36. Archived from the original on 2012-03-30. Retrieved 2009-03-07.