Brzeziński K., Zagórski J., Panasiuk L., Brzezińska M.:         
    
        
    Assessing levels of knowledge on the principles of pain management during post-graduate education of physicians in Poland (2012 r.)
        
        Annals of Agricultural and Environmental Medicine 
                
                    2012, 
                            Vol. 19,   
                                        4,   
                
            
                                    851-856