Heath Company. <br/><br/>
Operational Manual for the Heath Educational Analog Computer :   Model EC-1 

 - s.l. :   s.e.,   1959. 
 - p. 38 
<br/><br/><label>Subjects--Topical Terms: </label><br/>COMPUTADORA ANALOGICA<br/>MODELO EC-1
<br/><br/><label>Universal Decimal Class. No.: </label>681.332[035]