Mathematical Reviews 

 - United  states American mathematical society      1977 
 - various pages  cm. 
<br/><br/><label>Standard No.: </label>154724 
<br/><br/><label>Source: </label> Reference Collections 
<br/><br/><label>Dewey Class. No.: </label>"Bm .73 . N77, L7 .54 (4 -6 )"