Ehlers Victor M. <br/><br/>
Municipal and rural sanitation / 
Victor M. Ehlers and Ernest W. Steel. 
 - Third Edition ; fifth impression. 
 - New York ;  London :  McGraw-Hill Book Company,  1943. 
 - XII, 449 stron :  ilustracje ;  23 cm. 
<br/><br/>Indeks.