Fondell E, Lagerros YT, Sundberg CJ, Lekander M, Balter O, Rothman KJ, Balter K. Physical activity, stress, and self-reported upper respiratory tract infection. Med Sci Sports Exerc. 2011 Feb 1;43(2):272-9.
Knoll S, Jochum D, Talbird S. Comparative cost benefit analysis of two new Pneumococcal Conjugate Vaccines (PHiD-CV and PCV-13). Klin Padiatr. 2010 Jun 1;222(Suppl 1):S51-2.