Ritter, William Emerson,  1856-1944. <br/><br/>
The simple ascidians from the northeastern Pacific in the collection of the United States National Museum / 
by William E. Ritter. 
 - Washington :  Government Printing Office,  1913. 
 - p. 427-505 :  il. ;  25 cm. 
 - Proceedings of the United States National Museum ;  v.45 .
<br/><br/>Bibliografía: p. 501-504. 
<br/><br/><br/>Inglés 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Sea squirts--Pacific Ocean.
<br/><br/><label>Subjects--Index Terms: </label>Ascidias. 
<br/><br/><label>Dewey Class. No.: </label>596.2