Factors Associated with Dual Practice in Surgery Specialists: Application of Multi-Level Analysis on National Registry Data. - Bayat M; Khalilnejad R; Akbari-Sari A; Harirchi I; Salehi Zalani G; Mirbahaeddin SE; Khodadost M; Jafari Pooyan E; Yaseri M; Shokri A (Iranian journal of public health, 2019)