Langmann, H. H. <br/><br/>
30th International Mathematical Olympiad.:  Braunschweig, 1989/ 
H. H. Langmann. 
 - [1st ed.] 
 - Bad Honnef:  K.H. Bock,  1990. 
 - 79 p. 
<br/><br/><label>Dewey Class. No.: </label>510.79  / L284