| 
       
                  ACKNOWLEDGMENT
                 
                
                OPEN ACCESS ‑ PEER‑REVIEWED
                 
       | 
  
| 
         DOI: 10.1590/S0102-76381990000200001 Braz J Cardiovasc Surg. 1990;5(2):1-1 Indicate this article | 
  
| 
       
                  ACKNOWLEDGMENT
                 
                
                OPEN ACCESS ‑ PEER‑REVIEWED
                 
       | 
  
| 
         DOI: 10.1590/S0102-76381990000200001 Braz J Cardiovasc Surg. 1990;5(2):1-1 Indicate this article |