Xu J, Evans J, Coon C, Copley-Merriman K, Su Y. Measuring patient-reported outcomes in advanced gastric cancer. Ecancermedicalscience. 2013;7:351. doi: 10.3332/ecancer.2013.351.
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.