Hirschfeld, Leonard <br/><br/>
Letter to the Editors.  [electronic resource] 

 -  Journal of periodontology  Sep 1977 
 - 610-612 p.  digital 
<br/><br/> Publication Type: Editorial 
<br/><br/><label>ISSN: </label>1943-3670 
<br/><br/><label>Standard No.: </label>10.1902/jop.1977.48.9.610  doi