Wolmar, Christian (22 February 1996). "Wrong kind of snow in tunnel...". The Independent. London. Archived from the original on 1 May 2022. Retrieved 21 December 2009.
Fowler, Rebecca (20 June 1996). "Why The Planet fell to earth". The Independent. Independent Print Limited. Archived from the original on 1 May 2022. Retrieved 22 March 2016.
"Obituary: Barry Porter". The Independent. London. 4 November 1996. Archived from the original on 1 May 2022. Retrieved 22 April 2011.
Wolmar, Christian (22 February 1996). "Wrong kind of snow in tunnel...". The Independent. London. Archived from the original on 1 May 2022. Retrieved 21 December 2009.
Fowler, Rebecca (20 June 1996). "Why The Planet fell to earth". The Independent. Independent Print Limited. Archived from the original on 1 May 2022. Retrieved 22 March 2016.
"Obituary: Barry Porter". The Independent. London. 4 November 1996. Archived from the original on 1 May 2022. Retrieved 22 April 2011.