Library congress classification:   Class q. science  
/Library of congress 
 - 5th ed. 
 - Washington:   The library of congress,  1950 
 - 285p. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Classification
<br/><br/><label>Subjects--Index Terms: </label>Library of congress 
<br/><br/><label>Universal Decimal Class. No.: </label>D 025.49LC