- 
    
      Geoscience Wisconsin Volume 14Ordovician-Silurian boundary of the Neda Formation
- 
  
  Ferruginous and Calcareous Oolites at the Ordovician-Silurian Boundary in Illinois1991 Journal Article: p. 1-21 
- 
  
  Paleomagnetic Studies of Rock at the Ordovician-Silurian Boundary in Wisconsin1991 Journal Article: p. 53-63 
- 
  
  Distribution and Age of Dolomitic and Hematitic Oolites near the Ordovician-Silurian Boundary in Nebraska and Kansas1991 Journal Article: p. 65-72 
 
 
      
       
      
       
      
       
      
      