W. E, Krumbein. <br/><br/>
Damage caused by cyanobacteria and fungi in plasters and casting covering medieval frescos in north german rural churches. 

 - Strasbourg-FR :   Universite de strasbourg institut de geologia ,   1983. 
 - páginas 27-29 :   Ilustraciones blanco y negro 
 - Irregular 
 - (May.1983) 
 - News letter    .
 - Universite de strasbourg institut de geologia . .