左:アーノルド・ローベル イラストレーション Courtesy of the Estate of Arnold Lobel. (c) 1979 Arnold Lobel. Used by permission of HarperCollins Publishers. 右:「ふたりはともだち」(1970)「おてがみ」スケッチ Courtesy of the Estate of Arnold Lobel. (c)1970 Arnold Lobel. Used by permission of HarperCollins Publishers.