by Berta and Elmer Hader. by Berta and Elmer Hader by Berta & Elmer Hader by Berta Hader, Elmer Hader by Gina and Mercer Mayer. by Herbert F. and Peter B. Schiffer. Roberta and the Renegade Berta and Elmer Hader Written by Peter, Nancy and Herbert Schiffer.