Mohammadiyan M, Movahedi M. Title Study of Biological Factors in the Air of Emam Khomeini Hospital and Shahid Zare Hospital in Sari in 2007. North Khorasan University of Medical Sciences 2010; 2 (2 and 3) :51-58 URL: http://journal.nkums.ac.ir/article-1-447-en.html