(The New York Times, Telegraph, Los Angeles Times - 07/12/06, Nature, AP, Reuters, BBC, VOA, Dnevnik, Mediapool, Πρακτορείο Ειδήσεων Σόφιας - 06/12/06, International Herald Tribune - 04/12/06, Nature - 02/12/06, Medical News Today - 01/12/06)
(The New York Times, Telegraph, Los Angeles Times - 07/12/06; Nature, AP, Reuters, BBC, VOA, Dnevnik, Mediapool, Sofya Haber Ajansı - 06/12/06; International Herald Tribune - 04/12/06; Nature - 02/12/06; Medical News Today - 01/12/06)