Hersing, Otto. <br/><br/>
U 21 rettet die Dardanellen. 

 - Zürich,  Amalthea-Verlag  [1932] 
 - 154 p.  plates, port.  21 cm. 
<br/><br/><label>LCCN: </label>af 48004542  
<br/><br/><label>Subjects--Topical Terms: </label><br/>World War, 1914-1918--Naval operations--Submarine.<br/>World War, 1914-1918--Personal narratives, German.
<br/><br/><label>LC Class. No.: </label>D591  / .H45