Saxén, Lauri <br/><br/>
The Development of the Visual Cells. Embryological and Physiological Investigations on Amphibia 

 - Helsinki :   Suomalainen Tiedeakatemia,   1954. 
 - 93 p. :   láms. ;   18 cm. 
 - Annales Academiae Scientiarum Fennicae. Serie A. IV. Biológica ;   23 .