Cover of May I Come In, 1969. Cover perhaps illustrated by Lois Elhert. (Full credits list Marilyn Bass, William Baum, Tom Cooke, George Guzzi, John Kuzich, Jerry Pinkney, Donald Silverstein, Lynn Sweat, Joseph Veno, Jean Winslow and Fred Witzig.) Think what you will about children’s books, but this one has some really great, technically interesting illustrations. Cheap on Amazon, all the Ginn & Co. books from this time period are really great. Buy them and scan them!