Pidot, George B. <br/><br/>
Modal cities / 
George B. Pidot, John W. Sommer. 
 - Washington D.C. :  U.S. Environmental Protection Agency,  1974. 
 - 55 p. :  ill. ;  29 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Cities and towns--Classification.<br/>Cities and towns--Mathematical models.--United States