Aubert, K.E & Ljunggren, W <br/><br/>
Proceedings of the 15th Scandinavian Congress, Oslo,1968 
Ed by K.E. Aubert & W. Ljunggren 
 - Berlin  Springer  1970 
 - 162 
 - Lecture notes in mathematics 118 .
<br/><br/><label>Dewey Class. No.: </label>22  / AUBE