Boutros, Daniel. Sonic the Hedgehog 2. A Detailed Cross-Examination of Yesterday and Today's Best-Selling Platform Games. Gamasutra: 5. 2006-08-04 [2006-12-08]. (原始内容存档于2012-02-25).
Daniel Boutros. Sonic Adventure. A Detailed Cross-Examination of Yesterday and Today's Best-Selling Platform Games. Gamasutra. 2006-08-04 [2006-12-08]. (原始内容存档于2011-08-26).
Boutros, Daniel. Sonic the Hedgehog 2. A Detailed Cross-Examination of Yesterday and Today's Best-Selling Platform Games. Gamasutra: 5. 2006-08-04 [2006-12-08]. (原始内容存档于2012-02-25).
Daniel Boutros. Sonic Adventure. A Detailed Cross-Examination of Yesterday and Today's Best-Selling Platform Games. Gamasutra. 2006-08-04 [2006-12-08]. (原始内容存档于2011-08-26).