Lotspeich, William <br/><br/>
Discoveries in science :   :  how they are made 

 - New York :   Fawcett Publications,   1968. 
 - 124 páginas :   2 h.; 18 cm. 
 - Ladder : 2000 words ;   L-52 .
<br/><br/> This Ladder Edition has been especially prepared for the beginning reader.This edition is for readers for whom English is a second language. It can be anyone whos has learned 2,000 words of english. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>CIENCIA
<br/><br/><label>Subjects--Index Terms: </label>TEORIA DE LAS CIENCIAS