International Referral System for Sources of Environmental Informati on :    operations manual. 

 - [s.l.] :    [s.n.],    1975. 
 - v.  ;    30 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Environment Information -- Handbooks, manuals, etc.
<br/><br/><label>Dewey Class. No.: </label>PF 333.7 UNI