Weckroth, Johan <br/><br/>
Studies in Colour After-Images :   presentation of Basic Data and Previous Studies, with some new Observations and a Theorical Discussion 

 - Helsinki :   Suomalainen Tiedeakatemia,   1964. 
 - 110 p. :   il. ;   18 cm. 
 - Annales Academiae Scientiarum Fennicae ;   Ser. B, 134,1 .