International field year for the great lakes :  no.6 

 - Washington, D.C. :  United States Government Printing Office,  1973 
 - iv, 67 p.  ;  30 cm. 
<br/><br/> IFYGL bulletin no. 6 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Water chemistry<br/>Hydrology
<br/><br/><label>Dewey Class. No.: </label>551.48