World Health Organization <br/><br/>
Determination of airborne fibre number concentrations : a recommended method, by phase - contrast optical microscopy (membrane filter method) 

 - auth., Geneva  1997 
 - viii,53p figs. 
<br/><br/><label>ISBN: </label>92-4-154496-1 
<br/><br/><label>Dewey Class. No.: </label>614.71 WHO