Influencing factor analysis of left atrial thrombus or spontaneous  echo contrast in patients with nonvalvular atrial fibrillation
Xiao Pengfei，Li Guangping，Ye Lan，Xu Gang，Liu Xia
Clinical Focus . 2016, (5): 516 -519,523 .  DOI: 10.3969/j.issn.1004-583X.2016.05.011