"Amendment No. 4 to Form S-1". U.S. Securities and Exchange Commission. 10 February 2006. Archived from the original on 22 April 2016. This article incorporates text from this source, which is in the public domain.
Pearlstein, Steven (8 December 2004). "... And Another Thing". The Washington Post. Archived from the original on 9 November 2012. Retrieved 23 May 2010.
Pearlstein, Steven (8 December 2004). "... And Another Thing". The Washington Post. Archived from the original on 9 November 2012. Retrieved 23 May 2010.
"Amendment No. 4 to Form S-1". U.S. Securities and Exchange Commission. 10 February 2006. Archived from the original on 22 April 2016. This article incorporates text from this source, which is in the public domain.