How things work. 

 - 1975 ed. 
 - Chicago :  Field Enterprises Educational Corp.,  1974. 
 - 336 p. :  ill. (some col.) ;  26 cm. 
 - Childcraft, the how and why library.  v.7. .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Industry.