Determination of airborne fibre number concentrations :  a recommended method, by phase-constrast optical microscopy (membrane filter method) 

 - Geneva :  World Health Organization,  1997 
 - 53 p. :  ill. ;  24 cm. 
<br/><br/><label>ISBN: </label>9241544961 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Air pollutants, Occupational--analysis<br/>Environmental monitoring--Methods<br/>Microscopy, Phase--contrast